Most of the new features in both DLC ... are just "for fun"
Fun is kind of the point, though. The problem is that they're not enough to actually be fun.
Yeah, sorry I was not very clear. What I mean is they don't actually add to the gameplay, it's just something you can do because it amuses you or whatever. Like for example, plantoid DLC. Making your race plantoids (instead of humanoid or whatever) does not
do anything. It does not help you, it does not hurt you, it does not add new interesting challenges or anything. It's just something you can do if you want.
Most of the additions in the DLCs are the same. Yeah, you can make megastructures, but they don't add anything to the gameplay (except maybe rushing habs but even then probably not) - they come too late and are generally not worth the cost. They don't help you win, they don't help the AI win, they don't add meaningful decisions to the game... it's just another greeble tacked on to make the game look more complex. Ascension perks, a lot of the new race options, etc... it's all the same. It's just something you can do that does not actually make any real difference to the core game.
That's not to say "for fun" stuff is bad, or even never worth buying, just that I feel like they are charging "gameplay DLC" price for what is, essentially, fancy cosmetic DLC.
Also yes - if you play to RP or screw around whatever things might have a different value to you. My perspective is playing the game as a game that I'm trying to win. Maybe that's the "wrong" way to play a paradox game, but that's how I'm valuing it.