Safety Razors caught on because Mr Gillette gave them away, for free (initially) with a supply of blades and most men (and women) hated shaving with a straight with a passion. Here was a razor which tended not giving you cuts and you just popped in a new one every day or two or maybe give it a ride on the Lillicraps for a longer residence. Hones, strops, band aids were a thing of the past. New blades were cheap and it gave a pretty good shave that lasted until the next day. Maybe not as close as a straight but who cares (har har).

Gillettes genius was tying you to buying the blades for the rest of your life.

We here forget it's more a hobby with most of us.