Put a "Stop Generating Random Townies" Button in the settings

So, this is a known thing. The game needs random Sims to fill NPC jobs. There are roles that aren't playable jobs, and for whatever reason the game generates a new Sim for those nonplayable jobs rather than using, say, Bob Pancakes as your stall vendor. (Eliza seems to show up a lot in the science career in my saves, though, for some reason.)

There are a couple of things that people recommend, but they're all mods.

1. There's a mod that is behind a permanent paywall that people frequently recommend but I'm going to not do that because I've never used it--I don't use permanent paywall mods. You can find it if you want.

2. MC Command Center has a feature that imports random townies from your tray. I use this a lot, and semi-regularly go to the gallery and download cute Sims to spawn in as townies. This completely ignores their skills and traits, though; it just uses their appearance. This is mostly good enough for my purposes, as I just don't want a lot of hideous fashion disasters walking around my game. You can also go out of your way to download diverse Sims to put in your tray, and I highly recommend this as well. The game doesn't always do the best job of generating minority Sims, in my opinion.

3. Zero has a mod called "Assign NPC Role" and I've experimented with this. Once you do this you can't play them, of course, but it does work. I created Sims (well, tray Sims, see above) and assigned them NPC roles in the acting career, and when my actress showed up on set they were the director, producer, etc. Then I went to the park and my assigned gardener showed up to garden there. I mean, it's hilarious that Guillermo de la Cruz from What We Do in the Shadows always ends up the costume guy on set and Parker from Leverage always ends up the gardener, but... This might be more than you want to do, but I did it as part of setting up my starter save. It's really nice that the mother of one of my townie teens is an NPC gardener, and I enjoyed setting up a household with a Nanny mom and a DJ Headliner son...

Between 2 and 3, I'm mostly satisfied. If someone is generated in that's too hideous, I just delete them and let MCCC spawn in someone from my tray.

Sadly, for console players, I think you would have to just give fashion makeovers to all those Sims as they spawn in, yikes. ☹️

This is the point I was going to make.   The main excuse is "The Game needs NPC's to man stuff", but it doesn't cut it.   Why can't the game use NPC's that are already there in the game?  I have hundreds of unplayed townies that I've placed in the world from my library.  Most of them are unemployed and could be used.  And even if they were all employed, why not switch their career so they fill a needed NPC role?  It doesn't make sense that the game just keeps generating more and more townies for this reason.  And the game generates them non-stop regardless of whether there are roles to fill or not.  It's ridiculous!   But not as ridiculous as most of them look! 

I've even tried to get around it by manually assigning the needed NPC role to my own townies, but NO!   The game ignores the NPC I've just given the role to and goes and generates its own NPC for the role anyway and uses that NPC instead of the one I have just assigned!   I mean that seems like they are intentionally going out of their way to make sure the player is forced to do things EA's way instead of their own way.  Crazy! 

So Yes, I agree, there needs to be an option to switch this insanity off.  Have the game use townies already in the game to fill NPC roles and if there aren't any, then fair enough, generate one.  There used to be mods that did this, but now they don't work in later versions of the game.   It's very frustrating having to go in to manage households and delete stupid looking sims all of the time. 

I want to play in a world designed by me, without it being invaded by a bunch of random ugly clowns showing up everywhere!