I'd be happy to pay 20 euros a year for a single expansion pack that contains the content of 3-4 DLCs. It'd be a lot more user-friendly on Paradox's part and I'd feel a lot more comfortable giving my money. Right now, I essentially pay the same amount, because I will usually wait for a big sale before I catch up on DLCs (and I'm always at least 1 DLC behind because of it). From what I understand this is what most players do, and this is always the most popular recommendation to new players popping up on the subreddit. If you offered it all in 1 expansion pack, then it would just make things a lot more convenient for everyone. You could keep cosmetic stuff separate and keep making a good profit from the separate sales of those, from those who want to give a little extra for something that doesn't affect gameplay at all.
The complaint isn't just that gameplay gets locked behind a steep price tag, it also screws up the development of gameplay, since there's very minimal interaction (if at all) between features of different DLCs. Recently, efforts have been made to remedy this, but they amount to very little compared to the potential. Instead of having building blocks relying on each other and creating something beautiful and functional, the current model just spreads them all over the place, arranged in neat geometric shapes that are pretty at first, but can get stale after a while.
The complaint isn't just that gameplay gets locked behind a steep price tag, it also screws up the development of gameplay, since there's very minimal interaction (if at all) between features of different DLCs. Recently, efforts have been made to remedy this, but they amount to very little compared to the potential. Instead of having building blocks relying on each other and creating something beautiful and functional, the current model just spreads them all over the place, arranged in neat geometric shapes that are pretty at first, but can get stale after a while.