I am not aware of any software that I use that refrains from releasing new versions until the current release version is bug free. Perhaps there are exceptions, but that is just not how software development generally works. To be clear, I don't think it's unreasonable to want Embarcadero to fix bugs, I do too. But complaining about Delphi 12 coming just because Delphi 11.3 isn't bug-free is not reasonable or useful, IMO.
For what it's worth, I use Delphi 11.3 all day long. It is the most stable Delphi has been for me in years. I do not regularly experience the kinds of problems you describe, and pretty much every time I have, I could track it down to a component package. I do often have to restart Delphi when I am rebuilding packages or changing packages. It's an area that could use some work but I also understand what is happening -- I have a lot of components installed and any bugs in those components can affect the whole IDE.
My biggest complaints have to do with invalid syntax highlighting between ifdefs that the IDE isn't interpreting correctly although compiler works properly. And, CTRL+Clicking doesn't always locate a symbol definition when CTRL+G does, and vice-versa (so I can't just use one or the other, I am often forced to try both methods).
But, right now, I am able to use the IDE all day long with relatively minimal frustrations.
I'm not trying to disregard the issues you are having, but being realistic means understanding that if Delphi is going to get bug fixes, they have to be able to get revenue, which means sustaining subscriptions, which means shipping new features. As I said before, it is what it is.