Stirling Moss is considered the greatest driver who never won the championship. To be respected by your contemporaries in a competitive milieu should be championship enough for anybody.
Racing in that time and place was a blur between amateur and professional sport. It wasn’t professionalized, but money was involved. It wasn’t until there was a lot of money on the table that people were attracted to racing simply because there was a big pot to be won.
The word amateur is based on the word love. You do it for love. You can tell that Stirling Moss did it for love. He loved racing, and winning. He might have been the first driver to take making money at racing seriously, but he wasn’t in it strictly for dough. They went slower than racers do now, risked more, and had more fun, I think.