Unrealistic timelines, implementing what should be backend logic in frontend, there's a bunch of ways SPA's tend to be a trap. Was react a bad idea? Can anyone point to a single well made react app?
As you point out it's wildly successful and is the backbone of many groups internal communication. Many companies would just stop working without Slack, that's a testament to the current team's efforts, but also something that critical would merit better perfs.
I'd make the comparison with Figma, which went the extra mile to bring a level of smoothness that just wouldn't be there otherwise.
Slack puts a nicer shade of lipstick on the pig than Teams does, but the lips still belong to the same thing.
I absolutely should. I hate how many applications have a UI that won't let me copy-paste an error message to search for, much less a menu item; who could possibly have thought that was a good idea?
Well, that's a valid framework too, but by the practical standard of goodness – the best of trash is actually good — because you don't judge goodness against some abstract ideals, but against available choices. Both are valid frameworks, but only one is useful in practice.
It’s best in class because everything else is worse. It’s a sad state of affairs.