Um, I have very mixed feelings about KI.
It's probably my favorite to watch and I kept up with the last year and a half of its competitive life. The overall presentation and design of a lot of the characters is really strong. I've only played one person but it feels like it's probably better online than MK11. It's had a decent player pool all along from what I gather, even outside of the past few days where it seems to be getting some momentum again (It surged for a few days like 6 months ago too, so this isn't the first time). However, playing, spectating, and appreciating are different things.
I originally labbed it for a couple of days, and couldn't get my head around the combo system. After taking another shot at it, I've been able to kind of get past that, but it's still super awkward. It's largely the same across cast, but it seems like they all have some quirk that prevents you from transferring your muscle memory from on to another, like Saburwulf being able to inject extra auto doubles, or Hisako being able to delay the second hit of M/H auto doubles.
There are a lot of ways to open people up and get them comboed. Then you have to continue to be very active mentally during combos since they aren't set, they can be broken, since they can be counter broken. It makes the game very taxing. It's a game where you have to constantly guess about what is going to beat what, and it's all happening on turbo. It's very young man's game in that, so maybe 25 years ago.
I generally just don't like fast, full nutty in my fighting games. I'm sick to death of hearing about Marvel. I don't like tag games, I don't like full on insanity. I like MK11 that gives me more focused lines of thought and a week to hit confirm Kit's b14; which I still somehow manage to not confirm on the regular.
That said, I think once I really got DOA it turned into my favorite fighter, and I could say a lot of the same things about it that I do about KI. You don't have set combo routes, your combos can almost always get broken, you never get a metal break (unless someone is airborn), and you are constantly thrust into trying to out read the other player. There is a lot of overlap, so I don't fully get why it works in one and not another. The fact that it works in one that nobody plays, vs the other that lots of people play, has great netcode, and is artistically more impressive is a bit annoying. They do feel like very different experiences though.
I may mash in KI on occasion, because it has such a strong and enduring cool factor to it, but I really don't expect to play it much or very often. If for no other reason that there are just too many games already that I can't get good at. I just payed $100 a couple weeks back for Granblue so would like to get my coin out of it at some point, but it's hard to even get a good connection despite having players. It may not have players 6 months from now, so how long a window do I have to do that?
I have all the games, and even living by myself with no job, and playing with few stops there are too many. Have to make hard decisions on what I can play realistically. Everything from what can I get good at, how many people are playing, how much effort will it take, and how is the netcode, are all weighing factors.
I'd rather focus on MK11 and SC6. Unfortunately, SC6 is feeling pretty quiet and you are basically at risk of running into tournament players every time you play, but MK11 still has a fair number of players (at least on PS4. PC is becoming another matter). I still can't micro-duck, I need to less lazy about hit confirms, I'm not always considering my position, and my flawless blocks are really rough at times. There is plenty to try and work on in MK, and a lot of it is stuff that doesn't boil down to out thinking people.