Based on your enjoyment of management and strategy, Paradox's grand strategy games might be something you enjoy. Same publisher as Cities Skylines. There are four main series of them, each with their own mechanics but enough broad-scale similarities that knowing one helps with the others. They are:

• Crusader Kings, set in medieval Europe, North Africa, and about half of Asia. This one is the most roleplay-heavy, as you play as a succession of characters within a feudal dynasty rather than a country
• Europa Universalis, set from the European Renaissance up to the end of the Napoleonic wars. The whole world is playable, and exploration is a big mechanic
• Victoria, which covers the world through the rise of industrialism. This one is the most simulation-heavy, focusing gameplay around economic development and the diplomatic manoeuvring of great powers
• Hearts of Iron, which is the Second World War game. This is the one to go for if you want to play the military side of things

What distinguishes them from strategy games like Civ and Age of Empires is the greatly-reduced abstraction. There's no expectation of every starting point or playable country being balanced; if you start as Belgium in Hearts of Iron, you're going to have to do something clever to not get steamrolled by Germany. There's also no win condition beyond what you set for yourself. When I start a game of Crusader Kings, I'm not trying to win the game, I'm saying to myself "let's see if I can unite all of Britain and Ireland under a Gaelic ruler"

All Paradox games have quite a lot of DLC, but the base games are solid (often now including several of the earlier DLCs for free, in the case of older games) and they go on steep sales pretty often. If there's not a specific time period or mechanic that sways you towards one of the games, I recommend Crusader Kings 3 for the best new player experience