There were things that should have been in TS4's base for sure. But I agree with most of your list OP. Laundry doesn't magically happen ten years later it seems nonsensical to add that years later doesn't it? If we think logically what did those Sims who lived before Laundry Day do with all their dirty clothes? I look at things from a more pratical view I guess than developers who may be looking at a profit angle.
Sims should have dirty clothes in the base.
There should be some mild weather at least. Like some rain and light snow or whatever. It makes no sense at all in a fifth iteration that there wouldn't be some base game weather. Maybe not 'seasons' passing but at least some differences in temps and precipitation.
Yes, there should be kitchen applicances, like mixers, food processors, dishwashers, etc. What is the point of gaining wealth if there is nothing to buy to make a Sim's life easier. If not, then there should be a reduction of money earned if there are no luxuries to spend it all on to make their life easier. On that note, why have such an easy life if they can just be happy all the time doing dishes by hand etc. or using a mixing bowl by hand then there should be less happiness until they get those things, right? I know I would be.
One thing they can remove that was forced on all Sims in TS3 and TS4 is the cell phone, who is born with one? That is so ridiculous they get a free phone and never pay a phone bill...and all of them magically have one. Then people fuss about such things as unrealistic aliens in a base etc. Geez...think about the sillyness of everyone having a phone they didn't even have to go buy...or recharge and or pay a bill to keep.
Small pets, yes, hamsters etc. Maybe even the smaller birds, and not an expensive one. They can dream about that expensive bird on down the line.
Animals in the worlds, yes, I think it's way over due to see some wild life and animals in a base game. Depending on where your Sim lives there should be rabbits, deer, etc. Whatever is common in the world they are trying to imagine. And not FX.
Urban cities, yes, in a base game perhaps there should be a world that downtown is urban and the outskirts more suburbs and even farther out country style living. No need for multi worlds if done correctly.
Base game, I think it's past due there are different temps and weather and terrain all in one world. The higher you go the colder it gets. Mountainous areas should have a temp change, along with more arid, dry weather in a flatter, drier area of the map. Windy and more rain on hilltop areas in more wooded areas of one combined map.
School, night courses, higher education for adults, school activites for children, a community college. Private, Ivy league colleges could come later. But Sims should be able to attend courses after work, and or remote learning and attend skilled labor schools to become an electrician etc. This could possibly relieve the player from having to put all this stuff on a tiny lot they didn't really want to remodel.
There should be places to go and things to do, without DLC. Such as more than a bar, library, and museum. I mean how can we suspend our disbelief if there is no where to go for the Sims other than those basic places without anywhere to eat out, do laundry, watch a movie, a sports' event, etc. It is too much to ask players to believe that in TS5, there wouldn't be any consideration of a base with just a few places to go when 'if' it is going to call itself the fifth in a life simulation.
There are more things that should be in the base, such as an attraction system. What is the point of your Sims getting married and you have no idea why they get along or don't? Why should a player have to wait years (TS4) if ever to see why your Sim is attracted to another. This was ok in the earlier iterations but not anymore. The fifth iteration should be so much more detailed and robust. Just a slap happy put together expecting us to buy into it again, isn't going to happen this time.
