I have the watch 5, iPad Pro 2020, iPad Air, iPad 2, iMac (2010 and dead, won’t boot), and MBP (2007 and still kicking), and iPhone X.
I live in a small, one room apartment, and when I just announce to the air “hey siri”, I sometimes hear bloops everywhere. It used to be a crapshoot which device responded to me, even if I was holding one in my hand. But it’s gotten a LOT better.
A common thing for me, whether driving my car or bike or walking with airpods, is I’ll say “Hey Siri, text my gf …”. She lives 3.5 hours drive south of me and texting often in the day is important.
This morning I tried to do so on my MBP. I running the latest Big Sur Beta (checked this morning, still have 11.0, weird). I held the keyboard shortcut to activate Siri on my MBP and told it to text my gf good morning. She said she didn’t know who I was, or who my gf was, and gave me instructions.
I didn’t see the menu that she referenced. When I go to system settings, I’m signed in, all boxes checked. So I asked Siri “who am I” and she didn’t know but recommended that I go into contacts app and designate my contact card as me.
I did that, and now the “hey Siri, text my sweetheart …” works.