We become so far removed from our past we really have no idea what life was like back then.

While straights were the only way to shave most men used them. Most people couldn't afford a professional shave except for special occasions. Only the very wealthy had servants who could shave them and really most wealthy folks shaved themselves.

I don't know how you would verify this except by books about life during those times where they would just mention shaving in passing. This was just a very common thing like how did women wash clothes before automatic washers existed. Gee you mean they really boiled water and beat clothes and used fireplace ash to clean and washboards?