React is like nearly any other tool, use it well, and it's great. Well optimized React is lightweight to the client and a joy to test and debug. That said, Web Components are even better, but I'm guessing that's science fiction to you.
Most React applications do not end up like that in the real world. They turn into poorly architected over complicated nightmares, particularly on sprawling apps which is the reality in the corporate space. Not everyone is building hyper-focused single function tools which can be crammed in an SPA type framework. And the users suffer for this.
One of the finest turds I've seen recently is my electricity company's meter reading facility which is an over-engineered react interface for a single web form with two fields and a confirmation box. The whole thing pulls 590k down to do that and takes 5 seconds for the initial page load on an M1 MacBook Pro. That's the real end game for most people. The only reason it's like that is because the people who built it don't know how to do it any other way.
And lets be honest about Microsoft: they do everything from a front end or user interface perspective and randomly discontinue bad ideas about 5 years down the line. Like Silverlight, most of WPF, bits of ATL and MFC, an entire mobile phone platform that got rewritten. And their competing framework WinUI 3 doesn't even work properly. Their own O365 web platform is a fine example of where this turns into a buggy mess. I bet react is dead to them within 2 years on one of their schizophrenic switcharoos. The only reason they're into it now is to capture some market from Electron.
1) MSFT has already used React for far longer than 2 years.
2) They have basically never used the technologies you mentioned (WPF, Silverlight, WinUI). They offer them as UI toolkits that run in their Windows environment and that’s it. Their failure to market and support these technologies is independent of what they do for their own development strategy.
3) They bought GitHub and effectively own electron now. Many of their biggest apps are on electron (Teams, VS Code, Azure Data Studio).
2. Yes they have. Half their developer tools were rewritten in WPF, they offered huge stacks including CRM on top of Silverlight and a huge chunk of windows 11 front end is WinUI.
3. Teams fucking sucks. VS Code is heading in the same direction. I've never used Azure Data Studio.
Huh? Those are Microsoft's biggest apps? Not, MS Word, the NT Kernel or ... windows 11? The XBox operating system project? Outlook express? Visual Studio? ... Github?
I'll grant that Electron is used by a few teams at microsoft. But I'd be surprised if even 1% of microsoft's engineers worked on products built with electron.
I don't love Microsoft, but it's for the best they adopt a well known and rounded framework like React, rather than try to invent yet another of their own frameworks, like the ones you mentioned. I don't know why this has anything to do with Electron, since their React push is for their front end frameworks for their main corporate product, Office365 (or whatever it's called today).