it's getting mind-blowing!!!

I can relate to your situation. I would prefer a less feature-rich but reliable device. I deeply regret selling my Wahoo to purchase the 1040. It’s also intriguing that the device’s reliability has deteriorated with each firmware update. It was significantly more reliable when I first bought it, except for the frequent Varia disconnects. I wonder if Garmin’s cycling division underwent some kind of staff reduction or deprioritization. 

I'm not trying to be combative, just generally curious that if you've "been using Edge devices since 2010 and they've all had significant unresolved bugs," why continue using them?

I have been using Edge devices also since 2010 (Edge 800), and - yes - they are not always perfectly. But I love to have IQ datafields, and I love to have OpenMTB maps on my device. and I love the layout of the screens. I don‘t need (and use) most of the overflowing features, and I was and I am very happy with my Edges (1040 and 1050 at the moment). No crashes, no reboots, no freezes…

I’ve switched from wahoo to 1040 two years ago. I chose to switch because I was gifted a Fenix watch and I was enjoying the additional metrics provided by the Connect app. I immediately appreciated the way longer battery life and all the metrics. But I also immediately noticed the connection with Varia was ridiculously unstable, but other than that it worked fine. I kept my wahoo around for almost one year, until I eventually decided to sell it. 

just around the time I sold my wahoo garmin updated Connect Ui, with a much worse user experience compared to previous versions, soon after that every firmware update added some kind of regression (totally wrong grade detection, climb screen popping up when riding on flats or even downhills, crashes, freezes, insanely slow syncs or even total failure to sync, lost connection to power meter, wrong UI language, the current issue with varia where there’s no visible notification on screen, and some more I can’t remember right now). I do agree that updates occasionally fix some issues, the varia connection issue is long gone and the climb detection seems to be fixed now, to name a few. But over time, my impression is that software quality gets generally worse with each update, I’d totally run an older firmware version if that was possible, whatever version fixed varia connection issues, I should have kept that. 

While it is true some of these issues won’t impact all my rides, I ride frequently enough to have to deal with them multiple times a week. And some other issues, like the current varia one, is just always there. Rendering varia almost useless with no workaround provided by garmin. (To be fair, they told me to try the beta firmware, but I simply can’t do that, their release firmware quality is debatable, i absolutely don’t want to risk making things worse with a beta version that I would have no way to rollback)

with all that context, I’d answer your question with: all issues I faced so far where kind of annoying but I’ve been able to deal with them, most of them would oy happen from time to time, they were not bad enough to drive me out of their eco system.

The current varia one is a complete different beast, it’s a feature that’s completely broken, and the root cause is the same though, poor software testing/qa practices. And even worse, the way Garmin handles these issues seems to show they don’t care much for customers that prefer reliability over bells and whistles (no pun intended but bells and whistles is literally one of the new features of 1050). 

My conclusion is that I’m not part of the market segment Garmin is focusing on. maybe I never was, I can’t tell as I’m using garmin for about 2 years only. 

for me, it’s a matter of time, once I find a good deal on the good old wahoo bolt v2 or roam v2, I’ll grab one. They have way less features and much shorter battery life, but they work 100% of the time flawlessly (I owned both of these devices before)

it’s also kind of interesting that my experience with garmin marine devices I used before was completely different, they used to be very reliable, so either garmin quality declined as a whole or they just don’t have interest on investing in cycling computer market  

Why continuing using them if they're so buggy?  I'm an cockeyed optimist and, evidently, a glutton for punishment.  I keep expecting the new one I get will be an improvement, but they never are. Also, when I researched other brands, they seemed similar in that regard, so there's an element of the devil I know.

My Edge 104 again not syching wit Garmin Connect nor Strava.

What's going on here? Is Garmin close to the ALIEXPRESS LEVEL when it comes to qulity and UI???

This is the straw that broke the camel's back.
2 months ago Garmin offered a major update for the 1040 and introduced a bug that makes the 1040 slow between pages and profile selection.
It's still mind-boggling to wait 2 months to get a fix for the bug introduced with the latest firmware.
Garmin is aware of it though...
My old FR955 has more regular updates than the 1040, it's the last straw...
Here we are really talking about a bug that is annoying to use and we don't know why at times it works normally and sometimes it is so slow that several pages scroll with a lag, so on outdoor outings it is really annoying.
For me this GPS has nothing good except great autonomy, the rest is completely perfectible and the introduction of functionality such as ride group has no place for a GPS rather intended for cyclists who practice long distances and roaming, leave its social functionality to the 1050.
The 1040 should allow us to be guided correctly, be able to manage waypoints/waypoint distance to create long distance racing strategies, be stable on connectivity with ant+ sensors, the varia drops out on all outings for example, it is exhausting to use a device that is not transparent when using it.
Honestly, I would trade less functionality for more reliability

https://forums.garmin.com/beta-program/edge-1040-series/public-beta-bug-reports/i/edge-1040-series---25-xx-bug-reports/the-screen-is-not-as-responsive-25-19

bug introduced since 25.19 and yet knowingly distributed by Garmin

exactly that!!! Btw, yesterday, I just got a used bolt v2