Before long, I don’t trust it and I just don’t use it at all
Whether that’s the case for you, I think depends on a number of elements. Trust being the biggest one in my experience – and I’m talking about AI agents in general, not just Siri.

Chris Martin / Foundry
It’s all fine when things work (typically when sticking to simple tasks) but as soon as something goes wrong or is blatantly incorrect, then the next time I fire it up, I’m not confident it will be able to help. Before long, I don’t trust it and I just don’t use it at all.
I’m a believer in the truth that if you want something done right, do it yourself, so AI agents aren’t particularly suited to me and this is just my experience. However, you might find it to be a real life-saver and, if you put the work in to learn what’s possible and (unlike me) keep appointments in a digital calendar, for example, it will be infinitely more useful.
It can search across Mail, Messages, Notes, Reminders and Calendar primarily, plus it can see what’s on your screen. There’s now also a standalone Siri app where you can talk to it as well as see your history.