I feel a little the same, but I have a plan.

I leveled WHM and BLM to get into groups easier.
I Leveled BSM to be able to do DoH contet.
Leveling MIN to make money.

I have 2 classes I like and one meh class (Pugilist, Gladiator and Maurarder) left to play in ARR. So I'll be able to explore a lot of the world leveling away, And OFC every new class.

This way I can enjoy the current game to its fullest, Only things I've not done is Garuda (my PC was broken during the BLM days) CC win and Hard mode Darnus. I think it will work out quite well to enjoy all of 1.0 and ARR.