>>29339070Real answer, and this is something that clearly isn't really understood by most people here: Cover doesn't buy Ads, because Cover is an Advertising company, and what's the point of Advertising an Advertisement?
Hololive stream aren't something that needs to be advertised because they are the advertisements. The main product being marketed isn't 'streams', streams are just a medium for getting you to buy merch and watch concerts and pay for membership. Streams are a content farm for clips and sponsorships, which generate additional interest in casual viewers, who eventually might be converted into fans who spend money on related products.
Nijisanji is a company that treats streaming as a revenue source in itself, which is why they stream more as it is their income. Hololive is a company which uses streaming as a means to the end of selling something external to streaming, which is why they stream less.