We had that in Windows 98, it was Active Desktop. It was bloatish and a lot of people disabled it in order to get far more cycles. Heck, IE and Explorer.exe were the same.
http://toastytech.com/files/throboff.html
KDE3 did the same with KParts, but it was several times better.
Microsoft was ahead of its time in this. In 2020 we are ready for it. Moore's law has caught up.
It would be less efficient and more wasteful to continue things as normal where every program has its own Electron. People already use Electron type apps. New ones are being made every day. That's not going away. If Microsoft and Apple put this in the OS, it would decrease the user's resource utilization. It's a net win for everyone except maybe chip manufacturers.
As for desktop Linux, GNOME3 already works like Active Desktop did. The whole shell is JS (and the GObject mess down below). I have used a lot of desktop environments. I've been skeptical of the JS eating the world trend. But I have to admit it's smooth. I had bad experiences with KDE (Qt/C++). Not only does it look ugly, it segfaults constantly.
Would it have been better to make a desktop environment in something more, uhh, professional like Go or Java? Of course. But that's not what the crowd decided. There's nothing quite like React for native desktop GUIs. Regardless of your opinion of JS, you have to admit that the React way was a game changer. Since there are no alternatives, the path of least resistance is to simply use React as is for desktop applications, which is exactly what has happened.
If you think this is smooth, you must be new on IT. Xfce already was blazing fast in 2005, even against GNOME 2. Shell is a bloat disaster, and KDE > 3.5.10, a segfaulting fest, but 3.5.10 was rock solid.
I've literally been using desktop Linux since I installed Ubuntu in 2006 in the spinning cubes era. It was never good. Windows (except Vista) always had a snappier interface. Xfce and GNOME2 are fast, I'll give it that, but don't have any animations or aesthetics whatsoever (and yes that does matter--it makes you happy to use your machine). If all I cared about was resource usage, I'd not use a DE at all and only use something like dwm. GNOME3 is polished and works, the best and only free contender to Apple and Windows desktops.
Bloat is something only insiders care about. I care more about adoption of free software than I do about its quality in the academic sense. The way to get adoption is UX and looking nice. If you're trying to convince someone to switch from Windows, what would you show them, Xfce or GNOME3?
Myself, since Debian Woody, when 2.4 was an _optional_ kernel. On snappiness, it depends. On multitasking, KDE3 run circles over XP.
>GNOME3 is polished and works,
Not even close. It uses huge loads of RAM while Budgie, while using the same technology, is far snappier. For a current user, I'd suggest Solus with Budgie.
I've only ever used it on expensive hardware so maybe I'm biased.
I have to kill gnome-shell maybe once a week. That's a huge improvement over KDE.
Xfce to me is just too ugly to use. And it messes up my system with all these trash Xfce-only applications and mime associations (seriously what's exo-open and why is it still causing problems 2 years after I uninstalled xfce?).
KDE3 did the same with KParts, but it was several times better.