Oh, I can really add into that part:
When the Sims 2 was in development, they had the game almost finished, but there was a fire (This is a rumor, it wasn't confirmed) in the building that completely destroyed all the work, and that only thanks to an employee that had a version of the game in her personal computer saved the whole thing and they literally had to rebuild and fix stuff from that beta version. Not to mention that they also had to remove certain things at last minute because EA didn't want the game to look similar to Bustin' Out <- This is the most logical reason despite EA is known for cheapening instead of spending more money in game production.
The game was going to have a total different layout and Sim menu compared to the one that we know today, there were things implemented in the early stages that were later erased due to corruption (A common issue with the game that later on, Simmers managed to solve with patches or creating clean copies of the neighborhoods and other mods), incomplete files, glitches, and other things that they couldn't fix on time and had to partially remove.
Cars were going to be part of the Base Game, as well for reflective floors (that later, simmers created Custom Content with the files of Mirrors to use as carpets), Weather and mini scenario challenges, so yeah, the Sims 2 is completely messy not to mention that Strangetown was basically the most used neighborhood for beta testing and a lot of issues within the game do happen in that Neighborhood not to mention that great part of the accidental lore of Bella Goth, actually comes from the fact that she was the most used Sims for BT as well.