If anyone knows of any other city-building simulators worth mentioning, please let me know.
I feel the opposite.
I think SimCity's charm is just nostalgia. C:S is definitely more of a simulation, as it simulates individual vehicles, including commercial traffic. All the SimCity games before SC4 used a statistical model for traffic, and SC4's path finding was very unlikely to use highways and mass transit without a mod.
And with mods, you can make C:S look like a photo [0], or add outlights to make it look like Borderlands [1].
[0] https://www.reddit.com/r/CitiesSkylines/comments/axhrg7/stre...
An advanced city where most jobs are Co$$ and Co$$$ can actually be designed to have very little transportation needs at all because you can zone the high wealth commercial and residential buildings close to each other.
Simcity 4 definitely feels much deeper of a game to me than skylines, perhaps simply because it's complicated and I get a sense of joy figuring out the unintuitive parts.
To me it didn't feel like there were many challenges or ways you could irreparable damage your city in City Skylines. You could maybe invent your own goals, like creating a specific look to your city or building the most density possible while maintaing efficient transportation. But that's what I'd consider sandbox: using your own creativity on a blank canvas with almost no chance of entering a complete failure mode you can't recover from.
The SimCity games felt more like they were a challenge needing to balance the budget and build a sustainable city all while being resilient to events like disasters. Might just be me, but I never felt like I could fail at C:S; whereas in SimCity you could make a few stupid decisions or expand too fast and start losing money, and all you could do is watch the city degenerate into a wasteland that can't be gotten out of (without cheating anyways). That made it feel more like a simulation.
This. The only times I've irreparably crashed a city in C:S is when I've been purposefully going for achievements like "<50% unemployment for 6 months".
https://www.polygon.com/2016/5/20/11722342/simcity-launch-ea...
Both of them are beautiful, but I think SimCity really is more polished, visually coherent, and better balanced than Cities: Skyline. Which makes it even more tragic and frustrating that SimCity limits you to such a small lot size, because one of the best things about earlier versions of SimCity was backing way up and looking across vast urban sprawls, every road and building which you created with your own hands!
What Cities: Skylines really got right was user modding and extensibility!
Maxis (before EA bought them) held some user focus groups while developing SimCity 2000, and asked SimCity users what they thought about additional "plug-in" content. (I don't remember how they framed it, whether they mentioned "downloadable" or "add-on packs" or "user created content"). But in general, the users were strongly against it, because they said they wanted to buy the whole game up front, and didn't want to feel like they were being nickel and dimed to get the entire experience. (And now here we are with free-to-play games with in-app purchases, alas.)
User created content and expansion packs were crucial to the success of The Sims, and users rightfully complained about being nickel and dimed by a long series of expansion packs. But the vast amount of free downloadable user created content that's available dwarfed the fixed number of items available in all the expansion packs (but you still had to buy the expansion packs to get the base objects and features (like pets or magic), in order to use any user created content cloned from those expansion objects).
I am eagerly anticipating Satisfactory, which looks like a first person Factorio.
I’ll have to look into Satisfactory!
That's your google keywords, there are modpacks but I don't remember the names. They are useful because the configuration is important though.
I don't recommend going the Seablock way right away.