Garmin Swim 3 ???

But, frustratingly, the Venu 3S doesn't have drill mode for pool swimming

Closest for what we need is Forerunner 265, but it has tons of not needed features and settings for swimmers. Why to pay such a high price for features we don't need or use ?
The best is to be released dedicated swimming device with some basic everyday stats.

Yes, but I use my Epix2 without Always On (even in some activities, like running or cycling) and the battery life is similar to the Fenix6 Pro...

Sure, if stronger battery is added, no wonder. However if someone does not want to use always on, but hates the gesture turn on function, is there a normal usage habit with the amoled?

I feel that amoled is again a mumbo jumbo feature, what is pushed by the masses, but a useless battery eating function only.

Do you have an AMOLED device, even a smartphone? I will never go back, obviously...

I don't know about the masses, but I prefer the best...

Best visibility does not equal best overall performance. I prefer longer battery life over brighter display at a GPS watch.

BTW, I prefer regular watch over a smartwatch, I use Swim2 during sports activities only.

Lol, I'm talking about a Garmin Epix/Fenix, performance is not an issue...

In any case, I liked the Swim2, until it died suddenly and, go figure, by battery issues... 

I've had my 265 for about 2 weeks now and am really loving it.  Agreed its overkill if I am not a runner, but its also a step up from the Swim 2.  While the swim features look the same on paper, execution is much better on the 265.  The screen is much easier to read underwater, its possible to customize the data shown on the screens during a swim, and sound/vibration are much better.  Not to mention crazy battery life, more/better sensors like pulse ox/HRV, and better smartwatch functionality overall.  

Only gripe I have is that I tried Auto Rest on the 265 and didn't like it.  fwiw, I also never liked autorest on the swim 2.  It just wasn't accurate enough in knowing when I stopped.  For example, if I swam 2 50s with 10 seconds rest it would often bundle those into a single 100 with a slower pace.  So I was consistently getting slower average pace on my swims by 3-5 seconds per workout.  I went back to manual rest and I am happy.  That said, I was on a WearOS watch for a few months using swim.com app with their autorest equivalent, and it worked much better. So there is still room for improvement on that front but it could potentially be solved with an update if Garmin chose to do so.