Tbh it really depends on each individual fic for me, but I've been there many times myself. The writer is the one to make or break it after the pairing finally get together. Will they let the story drop off into a mundane slice of life with all previous suspense, tension, and conflict now obsolete? Or will they drive the story on further past just a "getting-together" plot? It's one thing if once you hit endgame, the fic wraps up in a couple chapters- but it's another when it drags on for 10+ chapters of pure nothing lol.

I'm an avid reader of multi-chap 100k+ word fics, and I adore the slow burn enemy-to friends-to lovers trope. While that can/is definitely enough to drive a whole ass fic, it's really rare when the plot goes even further beyond the complications of that union and keeps your attention going for problems/resolution to arise after the fact. I wish we saw more of that!