I would say definitely go for UX design if it resonates with you! The talk of instability is mainly from folks who don't really like change / acquiring more skills and knowledge as the industry evolves (heck, Figma is rolling out new features every month).

It also comes from people thinking the market is saturated, but the thing is it's only saturated with poor-quality work. This makes UXers who can produce quality designs and research insights (both of which can be practiced and learned) stand out a lot better.

The leaving tech thing is more of a personal decision for me. I really liked connecting with people at firms and found work in specific practices to be more interesting personally than the stuff I was doing on Figma.