I am a huge fan of grand strategy, and can play those kinds of games for hundreds of hours without getting bored. Sadly, there aren't a lot of options in the genre. I discussed this with @Boukert a while ago when we were looking through Steam for games. Outside of the Paradox games like EU4, HOI3, CK2 etc. there are only a handful of other decent games.
This means you're generally stuck with one of the following three options:
- Real time strategy
- Real time strategy with pause
- Turn based strategy
The first PC games I played were RTS games. The Total War series is awesome, and Rome Total War might even make it into my top 10 games of all time. The single player was fun, sandbox fights were fun and it is the only online RTS game that I was able to play and not be immediately destroyed by Koreans. There are other games floating around now that are similar - such as Ultimate General Gettysburg, which was actually made by someone from the Total War modding community.
The other options are lacking though. I am convinced there isn't a single good space strategy game that exists, unless you're including FTL. FTL is a decent game but it suffers from the same problem a lot of other games suffer from. You need to pause every 2 seconds to figure your shit out, so the game constantly stops and starts again.
An alternative is stuff like Starcraft, or even something like Cossacks. Resource based RTS, where the only "strategy" that exists is performing actions as quickly as possible. This of course means that you will be inevitably gangraped by Koreans if you try to play online, so you're stuck with the campaign or skirmish mode. Half of the campaigns in these games are terrible because they put too much time into making the multiplayer, so if that's the case then you're stuck with skirmish mode.
Turn based strategy is pretty solid. You know exactly what to expect most of the time. Final Fantasy is one of my favourite games, but the games also highlight a massive problem with the genre. All of the games from 1-10 have the exact same battle system, the one used in Pokemon basically. Pick an option, end turn, get attacked, repeat. As the games went on, they introduced some QTE elements that slightly improved the gameplay and made it a bit more interesting. X-2 introduced a battle timer that has been used in every game since. Essentially, each character has a specific amount of time to wait after they have performed an attack or used an item, meaning that sometimes you will be attacked twice before you can attack once. As far as I can tell, everyone absolutely hated this, and Square Enix has continued to fuck with the battle system in increasingly ridiculous ways ever since.
So in short, grand strategy doesn't have enough games, RTS puts too much emphasis on speed over strategy, RTS with pause doesn't flow very well, and turn based strategy has repetitive gameplay. But if you change it, people will hate you for it.
Fuck Koreans.
Sounds like your biggest issue with RTS is that you don't know how to git gud. :p
I'm more sympathetic to RTS in general; I was actually quite decent at Starcraft, and could win matches with some frequency online. I also had a friend who was interested in learning the game, and so I played many matches with him, teaching him as best I could, and going over replays with him and such. I found myself doing a lot of thinking while playing, and while you did have to be agile with what you were doing, that just didn't bother me so much. I find myself enjoying that less and less these days, and love the pause feature that many RTS games offer now.
Playing older-school RTS games on slower speeds (like Rise of Nations and Starcraft, both of which allow speed options for the game in the lobby), could be up your alley. You don't have to be quick like a twitch shooter, but everything still moves at a constant pace.
It's true Grand Strategy in general doesn't have a lot of games, and Paradox makes the lion's share of them. It's just a kind of niche market, so it's hard to break into it at all; I'm confident it can be done, but if it will be done is another question. Ultimate General: Civil War is a great game, by the way, and I've been having fun with it. You might try Sins of a Solar Empire for space strategy. I think it's the best real-time space-strategy game I've ever played. The game is not very quickly paced - despite being a somewhat standard RTS strategy game, which gives you time for thinking and decision making. You gather resources and tech, like normal, but the game allows for absolutely massive fleets, along with hero-like capital ships which level up and gain abilities. There is not a lot of variety in ship types, which is its primary downside. I have not looked, but I am sure there are mods within the community which help.
Galactic Civilizations 2 I can also recommend. it is turn-based, but combat between ships is done simultaneously, so it more becomes "can I engage here" than what you complain about in typical turn-based strategy. Fleet combat reminds me of EU4 army combat - it's more judging if a fight is good for you or not, and hoping for the best once you jump in. The flat nature of space doesn't permit much in the way of terrain, but starbases can affect areas around them and boost nearby fleets, so they function like fortifications in a way. There is a third game in the series, but my understanding is that it's slightly inferior to the full second game with expansions and all that. I may be wrong, so it's worth looking into.