With so many "me too" replies, it is easy to get lost in here.
The point I am trying to make is that, although all may be similar, in that there crashes or instability after installing Sonoma, the reasons for each may be different.
For a lot of people, though, Sonoma is working fine. I dare say it is the least buggy .0 version that I have seen in years.
To the "it's happening on my 3 macs, so it must be Sonoma" I would like to note that most likely those three macs have pretty similar software installations, so whatever causes problems in one is very likely to cause it in the others.
Running Etrecheck and checking for old and possibly incompatible software may give clues.
Also, if one can, installing a clean system may help determine if indeed the OS is the problem.
I have so far only seen one case where crashes happened on fresh clean install, and that happened to be caused by a failing drive.
Having crashes or badly performing software is bad. But deciding from the start that it's Apple's fault and not doing troubleshooting is not going to help.