Cities Skylines 2 just solved every road and traffic problem ever

There is so much rubbish made by Colossal Order for CS1 I'm sure they were just told by Paradox to do it and they're laughing at paradox.

There are just expansion packs though.

You can play the game perfectly fine with just the base. And if you want to have a little bit more traffic control you install some free mods.

For almost all DLCs apart from the really new ones, you can find keys for 2-3$ per DLC and half of them are unnecessary radio stations anyway. I revisited the game last year and had no DLC puchased ever, I spent about 15€ in total to get all the major DLCs up until then. Only for the DLCs and Content Creator Packs that came out after that I paid 10-15€ each.
Some of them may also be available for <5€ already and the Content Creator Packs could be replaced by free workshop assets if you want to save more money.
It's also worth noting that the game is 8 years old already and still getting new content.

Between mods, the base game, and maybe a DLC or two, you can play the game for cheap. It'll also likely be on sale with the upcoming Summer Steam Sale, so you could grab it for $8 and a few DLCs and be well equipped. It's sure to be a viable game for awhile given the great mods. Play CS1 while the inevitable kinks in CS2 are ironed out.