I agree with the observations, but Sketch slowed down to the pace where Adobe XD delivers features that were a top of the mind back when Sketch 3 was taking the industry by force, i.e. components with states.

Figma definitely invests more effort into community outreach (streams, social media presence etc.) as well as corporate sales. That seems to be working for them. They're eating the market share previously occupied by Sketch. It may be of sustainable. Future will tell.

Especially given that Figma behaves like a thirsty VC-backed startup

Why “like”? Figma is a VC-backed startup. As is Sketch. Are they any different? They are similarly VC-backed. They behave quite similarly. They are both quite secretive, prone to hype up superficial nice-to-have as features as though they are the best thing ever. Both are shamelessly exploiting community for free promotion and ecosystem cultivating, although Figma seems to be doing much better job here, at least with support for plugin developers.

The actual difference is that Sketch has slicker UI, while Figma is more performant and used to ship new actually important features faster. Most importantly being “cloud first” is at least half of the solution for the version control and design system CI and it's really hard to go back from that (even if Sketch now has an integrated cloud which is supposedly smoother than Google Drive, Dropbox or whatever). Figma slowed down somewhat these days though, becoming another slow giant with unresolved issues and features that community has been asking them for years which are maybe coming some day and maybe not.

Calling it an “editor” is disingenuous.

Add some hover styles.

Do the inventory → Identify different implementations of one pattern → Design new reference version of the pattern (or use the best from the previous one) → Rinse and repeat

the Reader becomes less aware of size content and could actually start reading it

That's just a theory though. i.e. have you considered that maybe you just significantly decreased readability and now people spend more time processing your copy?

Your website has no title and no favicon.

https://bjango.com/articles/colourmanagementsettings/

You can turn it off from either View menu or by pressing ⌘+⌥+T.

Basic version control is absolutely available to designers for free, but its utility is very limited. That is because version control for design source files is a much bigger challenge than version control for text files (that is essentially what developers' source files are). Multiple companies are working on a solution which can work as a companion for Sketch, some are working on extensions to git for its easier use with source files of different design apps. Some new tools are having it build in, functionality varies though. Basic level is what essentially Sketch does via integration to your Time Machine. I would like to add, that version control for developers isn't always free, you can set up your git or basic github account for free, but if you need those collaboration, continuous integration and other such stuff you're not gonna get those for free.