It's okay. The functionality is great, but that's pretty unrelated to it being a webapp. I often run into slowdowns when using it on my medium spec'ed laptop. It sometimes gets pretty bad. It consistently feels slower than using native desktop apps. The zero installation is definitely a perk, though a minor one. Plugins adding instantly and native collaboration aren't functions of it being a web app.

The trade seems to be a still quite noticeable performance hit vs no installation. It's probably the single best serious web app I've ever used, and I'd still trade it for a high quality desktop app if I could.

In my opinion, people have had their expectation dragged way down by shitty web apps so Figma feels good. It doesn't beat what tools like Photoshop used to feel like before their UI got rewritten in HTML and whatever fuckery they're doing now.