Crop and full frame are historical anachronisms based on 35mm film, which to be precise is a miniature format. It was always called that but became so popular - and 35mm cameras became so big - that 35mm became "normal" and other formats were re-imagined round the 36 x 24 standard. In the 1950s many people thought 6 x 9 negatives on 120 film as a normal snap-shooting and holiday format.
When digital photography took off SLRs were the biggest selling enthusiast camera, but sensor technology was sufficiently expensive that single lens reflex formats had to be rethought in smaller terms, with new variations in what people considered wide, standard and telephoto focal lengths. When prices dropped enough to put 35mm sized sensors in digital SLRs, people breathed a collective sigh of relief because the old numbers once again made sense. However that was only true for manufacturers invested financially and historically in SLRs, for other styles of camera there was little point in making compact cameras with big sensors, so Fuji, Olympus, Panasonic and others offer a range of wide, standard and tele primes to match their chosen format, while Nikon and Canon have relegated smaller sensors to beginners market, mostly, with a small range of semi-pro APS-C bodies and lenses aimed at longer focal lengths.
Digital has made a nonsense of older conventions, but they hang on in the minds of enthusiasts. Everyone else is using smartphones, the best of which will out-resolve most old 35mm cameras, and have larger teams working on their photo technology than camera manufacturers have on theirs.