If you started with a piano background when younger, old school playing comes naturally. Of course an arranger for single performing was a huge advance and opening to a wider range of material and style. I never played piano, but started with accordion. Then midi accordion with arranger modules. But some songs and styles didn't fit with the image of the bellows pumper, so I progressed to a hybrid keyboard (Orla models) with keys on right and buttons for left hand (ala Jerry T). Not to mention to just sit down, power on and go was way easier and more comfortable after back surgeries and age. Auto accompaniment afforded me starting with single fingering to start then working my way up to multi finger chording. Ill probably never be a full left hand old school player. I accept that I may not call myself a "complete" keyboard player, but I don't claim to be, nor do I require anyone else's label. I know there are many exceptions here, but I've known many piano style players who don't know what to do with bellows and buttons, a skill that is not yet extinct. The genres I play in still have me alternating from midi accordion to keyboard on just about every set, whether as a single or with 5 or 6 pieces. So its been where you started, followed by ability, and need, to change and learn.