This is a free-roam stealth-inclined open world game.
Best short description I can give is "GTA with stealth elements" - it plays exactly like free-roam GTA, except it also tries to spin itself as a stealth game.
The combination works, and the core of the game is very solid, but there is serious "ubisoft cancer" in it, too.

The main core of this game - navigating the open world, driving various vehicles, stealth-optional combat - all works quite great and is typically fun to engage with.
It definitely nails this whole " just a team of 4 dudes by their own deep in enemy territory" feeling.
It is possible to clear areas with a much higher enemy count without them ever noticing you, or just completely blow it and go guns blazing (optionally in a rocket-firing helicopter or cannon APC).
Either option works, but obviously in the latter the enemies will attempt to pressure you, which, depending on the difficulty, area, and your equipment (including vehicles), might be weak or downright crippling.
The game does not really iterate on itself or progress in a meaningful capacity much, but I found that it was good enough for the time the game required my attention for.
There is co-op play available, and I happened to have a friend who is fan of the game who joined me often so that definitely added to the experience.
Solo play is definitely possible though, and the AI squadmates that you get are downright cheating at times.

Everything around the core of the game is what I want to refer to as "ubisoft cancer".
Open worlds having slow moments is definitely not something specific to ubisoft, but there are definitely signature elements.
There is an absolute metric ton of various side objects and collectibles you can get, most of which do not really do anything for you.
Since there is a form of resources you can collect, collectibles for these resources just continually respawn all around you.
There are a lot of guns, a lot of which are locked behind ♥♥♥♥♥♥♥ loot boxes of all things.
Loot boxes and premium currency, in a damn single-player/co-op game.
Though, at least the guns do not really distract that much as while there are a lot of them there really isn't much of a reason to explore the arsenal - I kinda stuck with a completely overpowered sniper rifle and the same assault rifle for the whole game.
The core of the game does not change all that much as I mentioned above, this can be a huge negative if you are expecting progression or being forced into different scenarios - the approach is always the same, and the strategies are always the same.

Overall, despite the "ubisoft cancer" this is a really solid game.
Most of the cancer can be ignored, and if you can look past that (and have a friend to play with) this can be a really fun experience.
Would not recommend buying at a full price - there really isn't that much content (it just feels like there is because of open world), and just to spite them for putting extra monetization.

It's a fun game with friends, my first experience of Ghost Recon, but personally, there needs to be a new Splinter Cell

EAC is a bit of a stinker running on Linux for this game, but it works after a little bit of research!