Is this without the AI mod? That would be very encouraging indeed! I can regularly finish most of my games around turn 40-45, but often delay it to finish an extra path (to level up the leader, I'm always slower for eco than for culture). It would be quite nice to see a bit more pressure to actually win the game when I first can. I'm about to get to the late modern in my first post-game patch, I'm curious to see whether the AI in my game also makes more points towards victory – the previous patches somehow made them really bad in culture and economic in my experience.
An improvement that I've seen (but only with a sample size of 1 game) is Isabella – of all people – defeating Charlemagne in Antiquity and Lafayette in Exploration. Two civs out without any intervention from my side, and taken out by the same player seems rather novel.
Edit: I just opened the game to take a look. It's turn 40, I have 15 artifacts, Isabella has 5, Confucius has 2. So not much better than before. No one else is close to victory, as there is no progress in any other legacy path by an AI. This is Sovereign though, maybe it needs to be Immortal to get a competitive race going. What I'm also seeing is that despite 2 civs have been erased, no AI empire has more than 15 cities at this point. I'll turn on the AI mod again for my next game.