pontiff was one of the best fights in the game tbh (so far. i havent fought final boss or any DLC guys left)
off top of my head, the best fights in the game so far were Champion Gundyr, Dragonslayer Armor (minus second phase off screen magic dudes), Dancer of Boreal Valley, Pontiff Sulyvhan, Nameless King and Abyss Watchers. i would put Prince Lothric fight right after those.
Pontiff feels great because its another good implementation of a duel weilding enemy. Fume Knight was such an incredible fight in DS2 because of the duel weild, but he was a little more fun because one was just a straightsword with quick attacks and the other was the big bonk ultra greatsword with slower, more deliberate attacks. So it felt like two unique movesets, whereas Pontiff was just two fast swords. but still great. and the second phase of pontiff when he summons the spectral version of himself was such a great mechanic, since it telegraphed what he was about to do. they always duplicated attacks about a second apart, so you dodge the first one, and you know exactly how to position yourself to dodge and punish the main one. just a very cool and unique mechanic
gank fights can feel really bad, but if done right like 2nd phase of pontiff, just adds to the experience
i really wish dark souls series had a boss rush mode like sekiro where you can just replay bosses. only one that had something like this was DS2 where lighting a bonfire ascentic brings back the boss of the area but at NG+ level