What other 3rd party works with Garmin?

This isn't a BaseCanp issue. Having said that I have no issues using it. What exactly are you struggling with?

Thank you for your response.

To answer your question, I am struggling with the Base Camp product almost entirely. As a 30+ year customer of Garmin products, I upgrade my hardware based on new technology and the UX/UI experience. My latest $600.00 Zumo XT is an example of my willingness to purchase an updated product, that makes the complicated things a bit easier and quicker to perform. Compared to my other 8 Garmin products, this is by far, the most modern UI, and I delighted. 

But let's separate the "user issues" from the software unexpected results I have experienced well over a decade of use. 

Performance and stability
I'm unsure if it's only Mac OS, but the software freezes, slows, or does not recognize my Garmin products. This includes crashing and memory issues. And mind you, I am running a powerhouse of a laptop. (I need one for my work) 

So how about using it?
I would be brave to say that most Garmin users are not planning to learn Base Camp in a way we would learn to use AutoCAD. There’s a whole class of software that many people still defend fiercely because they’ve invested years learning it, or because “it just works” for their niche use case. Not everyone is inclined to become a super user, or cares to be one. In fact, I would argue that most Garmin product users would like something that makes the complicated seem easy to use. Let others that are inclined to dig in deeper if they like, but do not market a product for a general target market, that has a steep learning curve, and that is non-intuitive.

Why It Matters
Good design makes products easy to understand and use, simplifying complex tasks and minimizing confusion for users of all skill levels. Products should allow users to complete their tasks quickly and with minimal effort. Effective UI/UX can emotionally engage users, making the interaction more enjoyable and encouraging continued use. After all, Garmin is here to make money, not to support a forum.

Final Comment and Apology
I did not mean to use this as a "rant" rather I wondered what others were using as an alternative. I may have misinterpreted the "it isn't a Base Camp issue" and I do apologize. For some background, I have helped design software for Fortune 100's for 22 years, and sometimes cannot help myself from "leaning in". My hopes are that a lead Garmin product designer will read this, and see that their customers see software updates are just as important as their hardware updates.

For Those Users Interested
I found a few possibilities, although not free. 
MyRoute-app (MRA)
Furkot
Garmin Tread App
REVER
GPX.Studio
QMapShack

Just remember, there are lots of factors for choosing an alternative like Online vs. offline functionality: Decide if you prefer a cloud-based solution that requires an internet connection (like MRA) or a desktop application with offline capabilities (like QMapShack). If you use a newer Garmin device like the Zūmo XT2, the official Garmin Tread app offers the most seamless integration. If BaseCamp's dated interface is your main complaint, a modern, intuitive service like MyRoute-app or REVER might be a better fit.

Cheers!

And thank you for reconsidering and allowing this post. My intent was not to post an "inappropriate and abusive" post, but rather was to offer some customer feedback. I do appreciate the product support and commend those that offer it.