This one has said it before and may say it again.
While this one detests, loathes, despises, hates as they hate Helium double hockey sticks, Battle Passes as a system…
The one in this game is amongst the least odious that this one has encountered.

Another factor, both in the limiting and in the weekly rather than daily focus, is the CCP.
This isn’t supposed to be a political rant, not at all, but there are legal realities.
The NPPA has moved against incentives for daily spending of time on video games.
Tencent is based in China and it behooves them to not only obey the laws but act in a manner so as not to draw the ire of the governing party/administrations.
This is not a judgement or anything of the sort.
Capping daily BP gains and moving BP challenges from daily to weekly are very consistent with NPPA’s suggestions.
Realistically speaking, this may be a matter of legal expedience/regulation adjacency as anything else.