The first problem is that it's just slow. If I want it to turn off some light, it takes a long time before responding.
But yeah, the failure to do basic tasks. I have a routine that I used to have it run (controls several devices at once). Now:
10-20% of the time it runs it.
60% of the time it says it's running it but it doesn't do anything.
20-30% of the time it says it can't do it unless I opt in to invasive permissions. And when I opted into them, it still failed about a third of the time. So I opted out again.