Spam is something nobody wants. The influencers videos quite some people want to see despite their sneaky ads. So youtube gets views, too.
Spam is something the recipient doesn't want. What is or isn't spam is subjectively determined by each individual recipient. If spam were strictly determined by what nobody wants, requiring complete consensus, then nothing would be spam because in a world of 7 billion people there will always be one nut who welcomes the unrequested solicitation.