Future neighborhoods need to be smaller!
If you look at the neighborhoods in the newer worlds they always seem empty and abandoned - beautiful set-dressing and beautifully decorated but no sims around. If you take City Living for example, the spice market district feels so much more lived in since the area is more compact and therefore allows multiple sims to actually gather at one spot. Also there is always something happening, the street musicians, the random sims playing as the golden statue, the festivals, collectibles in the area. I wish for more of this in the future, especially since we do not have open worlds, we don’t need these huge areas.
Allowing more sims into one loaded lot would also solve this abandonment issue to some extent, but in-game performance would probably suffer from that. Smaller neighborhoods would save budget and would make the game run more smoothly in the following "few" years. For people with better performance PCs, there should be an option to increase the allowed sim spawning per loaded lot. (I think it’s set to 20 sims for now?)