Perceptually, it seems like coinbase over the years has become primarily an ethereum-centric company over bitcoin.

Why is this? I feel like I see a lot more initiatives toward eth l2s, wallets, ens, etc. than bitcoin-related products. Is this simply bc there's less surface area to build on? or it's less profitable?

They started as Bitcoin-only, did everything there is to do by like 2013

Coinbase is adding support for Lightning... that's literally the only new thing they could do since then (and there wasn't even sufficient demand until recently)