I think Figma is great. The folks at Figma are really adapting to the needs of modern design. Especially for non-MacOS users, Figma is amazing as it makes designing easier as you don’t need to use bulky Adobe apps. Having said that, Adobe XD is less bulkier and made specifically for this purpose of simple UI design.
I have used Figma personally in a couple of projects, the reason it does not fit in my workflow now is because I have gotten way too used to working on Sketch, and most plugins that make my life easier are on Sketch and no other tool.