There are several reason why the Pacific and Americas leagues are struggling in particular:
Japanese teams are playing poorly and it is one of the largest contributors to Pacific viewership so less incentive to watch when your region is bad.
Tenz is gone (Many people from Asia including many Japanese fans used to tune into Americas to watch sentinels and most of them are loyal to Tenz- not sentinels(there was a 92% Drop in Japanese viewership for Vct Americas this kickoff compared to the previous one)
The Japanese T2 league is by FAR the most popular T2 region they peaked at nearly 220k viewers in VCL Japan 2024: Split 2 so it probably explains a major chunk of the viewership from pacific.
Now I should also note that this years format is different so people might be waiting for the more important matches (elimination / Semi finals / Grand Finals etc )