Yes, ‘we was’ would definitely grate on me, and it’d affect my opinion of the speaker.
I once worked with a qualified EFL teacher who said it, and refused to adapt when speaking to her (Arabic speaking) students, even though it was confusing them. She was a very arsey type though.
Ditto people dropping Ts all over the place. I sometimes think they’re actually instructed to do it, even on the Beeb, in order to sound un-posh.
Ditto leaving the ‘g’ off ‘ing’ endings. Goin’, bringin’, etc.
And while I’m at it, people writing kinda, sorta, too, though I don’t see that on GN - plenty on MN though.