Except it's not a BP monitoring, it's some ML gimmick that detects signs of high BP. If it's like their sleep monitoring (which e.g. thinks I was in a "core sleep" while I was unable to fall asleep so I was sitting and playing a game), it's just a "maybe it'll work, but don't rely on this and don't expect any accuracy" type of thing.

Yes that’s correct but if it’s directionally correct it can be useful. My anecdote is that the sleep apnea tracking is directionally correct for me. It might not be for everyone but as long as it’s directionally correct it can be quite useful.

This. BP machine is like $50, 5x cheaper than a watch. And it's not like hypertension is suddenly onset.