I've encountered RP-ers in dungeons only once or twice; luckily for me they could spell, clearly had great imaginations, and were hilarious. I remember those few runs very fondly. They inspired the rest of us to join in, and we all had a blast, so there was no griefing about the duty taking too long. I can sympathise though if the RP element interferes with gameplay; dungeons aren't the place to take your Sylvie WHM (though that's a whole other can of worms)

RP done well is very entertaining. I don't RP myself - I don't have the self confidence - or not in FFXIV though I do play DnD in a game that's pretty RP based and it is huge fun. I'm a writer so my character does have a vast and intricate backstory that goes all the way back to pre-Calamity days but I wouldn't feel comfortable expressing any of that in an IC way. But if I encounter RP in /say and it's well done, I'll hang around to enjoy it. Bad RP I walk away, I wouldn't dream of reporting anyone for being bad at typing/writing in cliches/having a mediocre imagination

ERP though? Ewwww no thanks. Keep it to yourselves please. And if you don't, yeah I'll report you