I frequently get email notifications on my S24 Ultra before I get them on my desktop PC Outlook program.
That's my experience as well. Not just on my S24+, but the S20 FE before that, the S9 before that, the S8 before that, the BlackBerry Z10 before that...
That is to say, emails have never been a problem.
Now, for a long time, I had used the BlackBerry Hub for Android for emails, and of course the Z10 used the native Hub for emails that was built into the OS.
However, until the BB Hub adds MS 2FA support, I'm currently using the Samsung Email app, and i'm still getting instant notifications before even Outlook on my PC gets them. We're talking a second or two difference, so I'd say it's fairly instant.
Texts are pretty much instant. Texts with images may take a extra moment or two, but that's still quick enough for me.
Teams is also instant. But that's for work, so I do need instant for that, especially when I get a call over Teams.
How quick notifications from other apps are, I don't know. I've set very few other apps to even send notifications. I mean, it's not like I need anything instantly from LinkedIn or USA Today.