Even a larger company like Ableton is not supporting the previous version of Live in Catalina and won't release any updates for it:

https://forum.ableton.com/viewtopic.php?f=1&t=235803

The grandparent suggests that conservative users are to blame on this and that's partially true but it's not out of irrationality. If you are charging by the hour, you cannot afford any downtime. Studios run extremely lean teams and don't necessarily have a tech person on hand to fix things. If they find a configuration that works, they're going to stick to it.