Same, I miss having different characters that are specialized. One of my favourite things about FF is the different party members interacting with each other. Being able to control those characters made it feel more intimate to me. Comparing 9 and 10 (my two favourites) to 15 and 16 makes me really miss those moments.

If you liked 10's battle system I'd recommend the Octopath Traveler games to you. I've only played the first one but it's combat is very similar to 10, with some additional features. I've heard the second one is the same but has a better story and character interactions so if you don't feel like playing the first one I'd say you can skip it and go straight to 2.