Though it suffers from having as many different tones as the last thirty years of Dulux catalogues sellotaped together, I found in my XCOM 2: War Of The Chosen review that the latest expansion for Firaxis' game is an extremely effective remix of, basically, everything. But there's one very small change in WOTC that I didn't mention - a tiny thing with massive, massive repercussions for XCOM 2: War of the Chosen [official site]'s replayability.
There's a lot of things that XCOM does different to its more measured and unpredictable precursor X-COM, but the way you research new military technology is not one of them. Make a choice over what tech you want to unlock (or lay the groundwork for next), wait several in-game days or weeks for it to complete, do it again - each time agonising that you might have sold yourself short by, say, choosing weapon upgrades instead of better armour.
It's a system that I feel works very well - making a significant strategic choice that will very likely define your next few hours of play - but, depending on which iteration of the series we're talking about, it at worst forces and at best encourages a single golden path of research. XCOM 2 already dialled this down a bit by adapting the types of enemies you face to where your soldiers are in terms of tech, plus there was a wider range of XCOM soldier skills to call upon, rather than total reliance on firepower and armour. Even so, one can't really escape the 'I need Plasma weapons and the bestest best armour' stomp.
What WOTC introduces to solve this is your in-game scientists having flashes of 'inspiration', wherein they suddenly have a brainwave about a particular improvement. If you choose to take them up on their suggestion, they'll take significantly less time to research that tech - but choose something else instead and the speed-up offer will be lost. It's still a moment of dilemma, but this time it's not simply 'do I want X or Y' but rather 'do I want X enough to lose the opportunity to get Z super-fast?'
Because of this, I've spun off down totally different research paths than I'd planned to, and ended up getting certain techs way before I usually would - and others way later than I usually would. Compounding this is that inspiration can offer upgrades that are not otherwise available from Research or anything else in the game - bonuses such as one extra hitpoint of armour per soldier, or making stims reusable rather than disposable, or +1 damage on a certain type of weapon.
These one-off toys are irresistible, even if, moments before, I was absolutely convinced that I must have Powered Armour or finish autopsying Gatekeepers. It's both the immediacy of the bonus - concrete improvements to your existing squads rather than merely laying groundwork for what the squads might be capable of much later - and the idea that it'll be lost forever if I don't shift my plans over to it nownownow that motivates me so.
Every campaign, this stuff'll go differently. I'll research the core tech at different rates and in a different order, and may never even find my way to certain stuff, because instead I'm improving my military capabilities organically, in multiple and unexpected directions.
This all ties into other moves WOTC makes to prevent a linear stomp (such as broadening the ways to expand the resistance network and folding various one-off weapons from boss fights into the mix to reduce the need to reach specific weapon research milestones), guaranteeing difference every time.
Of course, it arguably also ties into that uncomfortable sense that XCOM has now fully become a game of outlandish superheroics and dubious internal logic. Why, for example, can scientists have a great idea about how to patch some extra plating onto armour now but will forget it about it later?
I've made my peace with this, more or less, but it does mean that we're not closer to the XCOM series replacing X-COM - both continue to serve very different purposes. If, however, WOTC sounds far too lairy for your tastes, might I suggest you have scan our 50 best strategy games opinion-o-feature for something a little more sedate?