paper when i can, electronic when i'm in a rush. and i'll own up to it, the only reason i get paper is because i just enjoy having a paper ticket. in 2019, i'm not worried about my phone dying, or it not being read. i simply like it. just reminds me of an earlier time of flying is all.
hell, if they had that waxy-style paper ticket from the 80's and 90's that carbon copies it a bunch of times, i'd definitely be all over that.