I've noticed that too, but the campaigns on BTT that pay $50/week usually have lower min post requirements. Comparing per post amounts, BTT still pays at least twice as much as ALTT.
Campaigns should not be viewed exclusively from the point of view of the participants, but also as the owner of the campaign. A number of posts, and boards that are counted... these are all just details.
The most important thing is the budget of the campaign, so there are campaigns on Altt that allocate more per week for participants than some campaigns on Btt. For example, now on Btt you have a campaign that allocates a total of $300 for 6 participants, once one CM participant alone received that much per week.
It seems that a new trend of small instant exchanges is coming, where there is a lot of competition and marketing will be the only thing that can set them apart from the crowd.