It's definitely not easy in terms of complexity. And it can be very challenging to surmount the obstacles the rng (or yourself) can throw at you w/r to world generation/placement. But it can be easy in the sense that once you understand the mechanics well enough, you start to notice certain deficiencies in AI behaviour that can be exploited. It is in fact optimal to exploit them.
E.g. the AI can't properly deal with a contiguous frontline. If it has significant technological advantage, it can pose a threat. Otherwise it will not make and exploit breakthroughs - rather, it'll tend to gradually reposition in response to your actions, which in effect allows you to advance your troops up to and beyond the cities it is trying to defend. So, you see, this isn't a bug you're exploiting that you could justify not doing. It's more like you pretty much have to form a frontline to check the threat from flanking/raiding behaviour, at which point there's little threat left.
Or, another example, the independents (minors, animals, 'barbarians') will not invade their neighbours, unless it's another major power. Which means that once you begin to border an independent province, even with a single hex, they can (and will) decide to pour through that new border into your territory. Similarly, whether alien natives or majors begin to interact with you diplomatically (which often consists of significant/impossible demands and a threat of war) depends on having/not having a border. And since the major difficulty, once the front lines are secured, becomes supplying and reinforcing your ever growing armies, it is optimal for your scouts/raiders/armies to not claim the last line of hexes between whomever you're at war with and the neighbouring provinces so that you don't suddenly have to put another frontline up there. Or when you conquer/diplomatically annex a minor city, and all of their territory changes ownership to your regime, the up-to-this-point stable borders suddenly overflow with all the indie hordes because now it's a fair game apparently. So, you either deal with the unrealistic-looking and frustrating invasions, or you end up with unrealistic-looking and frustrating to create borders.
Having said that, I've had >a lot< of fun learning its various systems, building logistical networks, and even just generating new worlds.