I organise my games into categories on Steam, two of which are real time strategies and turn based strategies. My collection of grand strategy games are in the turn-based games section. The reason is that simply put, the games have a lot in common with regular turn based games but very little with real time strategy games. This is why youtubers like DASTactics plays Paradox games when he does not like the genre of RTS at all.
First off, Stellaris is based on turns, the lack of an 'end turn' button doesn't change that, each day is a turn, they just happen to move on automatically, If you wanted to you could play the game as a turn based game, you could pause every day, make your decisions and move on. The difference between a game like Civilization and a Grand Strategy boils down mainly to scale. Paradox games have significantly more turns and each turn does less. In Civilization you'll get a significant amount of science, food etc. every turn, in Stellaris it's only ever 30 turns or so, the result is that an individual turn (or day) is far less significant in Stellaris or EU4 than it is in Civilisation, this means that providing the game is played on a slow enough speed, in general there is no need to pause.
RTS games test a very different set of skils, sure they test your strategic skills, same as turn based skills but to excel at a RTS you generally need to learn keyboard shortcuts, you need to be able to think on your feet, you need to be able to multitask effectively, simultaneously concentrating on macro and micro organisation. Testing those skills is not the point of a turn based strategy game and nor is it the point of a PDS grand strategy. The only difference between a player that plays purely with the mouse and one that plays with keyboard shortcuts is efficiency. DDRJake announced early on that he doesn't like using Keyboard shortcuts in Europa, Arumba is the opposite and creates entire mods to add shortcuts to the game and yet the former is undoubtedly the better player. Jake or myself (because I'm much the same when it comes to shortcuts) are not disadvantaged by relying on the mouse in a grand strategy game or civ but I would be in an RTS. You don't have to think on your feet either and can plan out moves at your leisure. Similarly you aren't generally under that intense pressure born from having to try to micro whilst also managing your production at home.
Again I will point out that grand strategy games appeal far more to turn-based strategy enthusiasts than they do RTS games enthusiasts. You're unlike to see someone who likes exclusively real time strategy playing Europa, you're very likely to see someone who exclusively likes turn based playing it though. This is simply put because again, they have very little in common with RTS games, and almost everything in common with turn based ones.
Of course because turns move automatically then some of these RTS elements can creep in in multiplayer where pausing is frowned upon, or if you set artificial rules for yourself about pausing or playing on a fast speed but they aren't part of the game's core purpose.