The only thing keeping you there is your own desire to retain the things that are...inside the garden. The Apple software. The services. The user experience.
The one thing I can see being upset about is losing access to the software you've purchased. But switching to Apple (or even Linux) from Windows/Android means giving up exactly the same things. That's not about a "walled garden": it's just a consequence of the fact that software has to be written, or at least compiled, for a particular platform, and significant extra effort has to be expended to make it functional across platforms.
Most apps I use are cross platform (Adobe CS, Cubase, Resolve), others are web based (Gmail, Basecamp, etc), my music is on Spotify, videos on Netflix and Prime, and my peripherals all work.
>Because you can't just leave Apples ecosystem unless willing to switch devices+ecosystem of course.
Well, I buy new laptop every 4-5 years or so. So if I want to move, I can always do so. If in a rush, I can always sell the old laptop in the first or second year too - with the added benefit that Macs keep their resale value better.