There's also the fact that an awful lot of what you're seeing is short stories, especially in yuri. The author simply hasn't enough space to make a fully developed romance in those constraints, so often has to pare things down to the very basics, or at least use culturally-recognizable shorthand. Longer stories can be a lot more decompressed, but even then it takes a lot of space to give the nuance of a real-world romance so it doesn't happen much even with hetstuff. So often you jump straight to love.
Now here in the west, you've also got the added layer that we don't often use different terms for "like" and "love", with the former being more of a children or friends thing. So literally every romantic feeling gets called love, the only difference in degree is a difference in emphasis. Which doesn't necessarily come off well in print.