There was a glut of pace from the 70s onwards. Obviously the WIs quartets: first Roberts, Holding, Garner and Croft; then later Marshall, Ambrose Walsh and others; Lillee and Thommo; Snow and Willis; the great pace bowling ARs, Imran, Botham, Kapil and Hadlee; the emergence of Wasim and Waqar under Imran, and a little later Shoaib; Donald and Pollock; then onto modern greats McGrath from Aus and Steyn from SA.
All this coincided with the increasing telecasting of cricket on TV so people could see how quick and hostile these guys were. It's also the point where cricket became more international. Midway through this time period South Africa were re-admitted, and India, NZ, Pakistan and the WIs were playing an ever increasing number of tests, so the opportunities were there for more players to emerge as genuine quicks. Dont forget also that each of those four latter teams only received test status at some point between 1928 and 1952.
So the majority of the early quicks could only come from Eng, Aus and SA.
I think it's easy to rank bowlers from the early/middle of the 1900s along with the best of the modern era. Larwood, McDonald, Gregory, Lindwall, Miller, Trueman, Statham and Hall all belong in the elite category. Saying they're "useless" is kind of offensive. There weren't as many because there were not as many test teams playing not as many tests, so less opportunity.
Early era (pre 1900s) bowlers is a different discussion imo, cricket was a very different game with regards to techniques, pitches and levels of professionalism.