If that had happened probably 30 of the episodes would be crap. There’s 12 episodes of FT because Cleese and Booth with 12 episodes they considered good enough, with a 4 year gap between those seasons. And the BBC tried to get more out of them, but they just couldn’t put them together. So yes we have “only” 12 episodes, but they’re 12 of the funniest half hours in TV history, and we don’t have to skip crappy episodes to get to the good ones when we watch it. The BBC model of “how many good episodes to you have” allows for a much more consistent product than the American model of “give me 22, and do em fast”.
And the episodes themselves have a much higher scene count than American TV show episodes do.