Not just British, a limited number 4-12 episodes per season is true for many European and some Canadian comedies and streaming drama and comedy series. Andor and Kim's Convenience had 12 episodes per season. Polish series like Krolowa have 4 and Gang Zielonej Rekawiczki has 8.

Interesting fact, the series 'Allo 'Allo was being marketed to American TV and in series 5, they made 26 episodes in an attempt to sell it to an American network.