I used to work for RBS.

I did a lot of Edinburgh trips but one of my team had the same flight every Monday and Friday.

the crew whilst not the same were sufficiently similar that they knew the regulars. So much so they used to arrange an on board Christmas party on the Friday night home before Xmas.

This was circa 15 plus years ago and I have. I idea how crewing works now so this may no longer even be possible for staff to be on flights so regularly.