You guys are incredibly lucky then. I ran about 7 to 8 extensions and had the whole shell crash 3 times on me over a time of a few weeks, making me lose progress. The journal logs weren't helpful, the gnome-shell just crashed and bailed.

GNOME only makes it possible to make Extensions via directly patching shell code and refuses to create an API. They can say whatever they want, this way of doing things is inherently unstable and will always break at some point, and it's not primarily the fault of extension devs or users if that happens given there literally is no other way of doing it. Even something as simple as the RunCat extension is potentially able to crash your whole desktop. This is comparable to every single modification you do in KDE being a KWin script (that settings window does have a warning in front of it for a reason). Another comparison: This is also similar to how Firefox did Extensions until they adopted the common extension API in Firefox 3 (?), before then that browser was known to be crashing a lot and become sluggish quickly since any extension was monkey-patching code into it - exactly what Gnome extensions do to work.

It's one thing to have a clear design idea, but Gnome took away so many freedoms (even basic theming) while merely providing an absolutely ridiculous way for even the smallest customization to then blame users and extension devs when something breaks or becomes unstable. It's no wonder people are upset. System76 outright began to work from scratch, meanwhile Linux Mint is providing libadapta as drop-in replacement for libadwaita to patch basic theming features back into programs that use it.

If Cosmic drops its version 1.0 and keeps its promises I'd bet a lot on Gnome slowly but surely declining. It does what Gnome doesn't want to.