I'd say yes and no. While companies are definitely more hesitant to go for long-running series nowadays, 12 episode anime were still the norm as far back as 2004 or so.
Just be glad that most anime don't have to deal with filler B.S. like in One Piece or Naruto. The number of filler episodes for those two are ridiculous.
12 anime episodes have been there since the past decade, but they weren't the predominant number back then as they are now. Nowadays, there are anime that are just 10 episodes plus an OVA in them.
Fillers are the causes to hundreds of episodes that were deemed unnecessary, making the anime series longer than it should be. Not every anime has to be 100+ episodes, it should be above 20 at least.