I stopped having any use of Dock other than seeing what windows/apps were still around that should have gone by now. But some apps keep toggling "keep in dock" for themselves so that makes it a bit more useless. Basically it shows what macOS has become – remove useful things, keep useless ones; repeat. There was a time aroound 2011-14 (or so) when this OS actually felt good coming from Linux distros. What worked for this company is the hardware competition esp. at fair prices just collapsed/vanished or at least severely lags behind.
Macs were at their absolute peak with 10.6 Snow Leopard. Unfortunately Apple badly ruined it with the iOSification update that was 10.7 Lion, with things getting worse and worse from there.
I think the death of Apple (and the birth of modern Apple) was iOS 7. Skeuomorphism, Steve Jobs being freshly deceased (RIP). The UI looked and felt like an undergraduate design project. The minimalism was pretentious and out of touch, and it's only gotten worse in my opinion.