I grew up in a pretty staunch neighbourhood. All my neighbourhood pals and seemingly at lest three quarters of the local lads were cream buns. I was about as catholic as can be, and it was no secret either. We went to mass every Sunday, to Carfin for random feast day celebrations and I was also an altar boy. I never heard a peep of sectarian shite come my way for the entirety of my upbringing. Not a bit. I was a known Jags fan, so my catholicism was pretty much irrelevant to them. In fact, weirdly, whenever they would sing Billy Boys after a title/old firm win they'd put their arm around me and expect me to fucking join in, as they knew I didn't like Celtic either. I know this is just anecdotal evidence, but I haven't heard of sectarian or anti-irish abuse outwith the context of Old Firm rivalry.
I honestly think that the sectarianism we have in this country is now completely separate from the religions it purports to involve. It's a divide tied up in the social identity of being a fan of either Celtic or Rangers and is honestly just a source of vexation to those practising catholics and protestants (all 57 varieties) who have no truck with either team.