Age of Wonders 4 is a game where I can clearly see the appeal, and I can see who this game is made for. That person is definitely not me, despite enjoying the game series that clearly was a huge inspiration for this series.
AoW4 lives in the 4X family, but it clearly has its roots in the Heroes of Might & Magic series with an empire management game bolted on top of it. HoMM's combat is delightfully simple and quick which is to its benefit. AoW ups the complexity, but that also ups the friction, as combat is a major part of this game. You can auto-resolve these battles, but doing so robs you of the strongest aspect of Age of Wonders.
So that leaves me with 4X-style empire management, and compared to its peers this is a weak aspect of Age of Wonders. Managing your scarce cities is just too simple. You're likely going to specialize in producing a handful of resources that best supports your strategy and not thinking too much about what your cities are doing aside unless you're being invaded. I like how you can be producing units and improvements simultaneously, but that's about the only mechanic that feels good when using your cities. Diplomacy with free cities just happens passively, though there are several options with negotiating with the other factions.
If you like HoMM and want something with management depth beyond that series, there's a lot to like here with Age of Wonders 4. There is a campaign that teaches you how to manage around ever-difficult scenarios and being able to place other leaders in your pantheon to customize "your" AoW experience lends itself to a lot of replayability. It is worth noting that if you take with this, prepare to open your wallet as this is a Paradox Game Studios game i.e. there are basically never-ending expansions. For me though, I want the depth in my 4X games to come from the empire management and that's where Age of Wonders 4 falls down, so ultimately it's not a game for me.