Interesting opinions. But mostly opinions, not backed by any data. Those features that the author considers to be "winning bets", might not be winners at all. Actually some of them may be considered Figma's downsides and maybe it would grow faster having had done things differently..

It all may be down to being relatively reliable (not that common among design & prototyping tools) and keeping the right balance between adding some slightly advanced prototyping features and still keeping it overall rather simple. Obviously I don't know the truth. Just saying it might be just that, and people are happy with it despite being browser based and without anybody really needing collaborative designing..