Yes, for setting timers and playing music on my HomePod. That’s about it.

Haven’t tried the “new” Siri yet as it’s not compatible with HomePods or iOS devices 15 and earlier.

Never. In fact, the annoyances of the occasional helpful "Are you trying to use Siri?" pop-up motivated me to turn it off.

Yes. To snooze my alarm, when it's across the room. She fails maybe 20% of the time, in that the audible portion of the alarm may not return after the snooze period.

Absolutely never. The last thing I want is to have to speak to my devices

No, I don't even remember the last time I used Siri.

It is just as useless as before, just slower

No.