If you haven’t read The Culture by Iain Banks, it’s among the best and most enjoyable sci-fi ever, in my opinion. The humans of the culture are quite near the most advanced in the universe, but there are entities more advanced, their own AI ships, prominently, but other species too that chose to “sublime” and exist outside of the normal universe, but because of that such ones are ever barely around. The humans of the culture could evolve that far too, but didn’t choose to do so yet in the series.