There's no such thing as an ideal world, just the one we have.
Let's Encrypt was founded with a goal of rapidly (within a few years) helping get the web to as close to 100% encrypted as we could. And we've succeeded.
I don't think we could have achieved that goal any way other than being a CA.
Sorry was not trying to be snarky, was interested in your answer as to what a better system would look like. The current one seems pretty broken but hard to fix.