an important upgrade to be sure, but most people take deterministic wallets for granted. segwit was far more memorable due to the block size debate reaching a fever pitch w/ the UASF movement. segwit activation and the launch of bitcoin cash was the culmination of several years of bad blood in the community. we've never seen anything like it before or since.
Yea for sure.
SegWit: most memorable
BIP39: most positive impact
SegWit simply had more conflicts in the community and drama in general hence it being more memorable. It's just slightly a bit less more important than the BIP39 in my opinion.