This also sounds different from my experience, no way I could have “taught myself” to fly. However, chair flying and mental rehearsals are always going to be a part of flying training, be it basic stick and rudder or tactical execution. No one sorts 6-9 targets efficiently without getting some instrucor led training, reading on their own, and going through it over and over...on their own before the training event and again after debrief.
You kind of id’d it yourself in your second paragraph, FLEA, at its current implementation the UPT Next is mostly just a different way to chair fly with shiny equipment.