bts mvs are made with a high budget as well and you really think bts or the members should be out there accepting collabs from every and anybody. They have such a huge popularity and influence that they resort to choosing their collabs wisely. So they limit collabs with the artists they genuinely like most of the time. Whereas with txt, they take any and every opportunity to get their name out there since they are not as popular. Hence why you see them "getting the most opportunities". It isn't rocket science.
Collabs are not about likes but money and new markets.
Which is why bts is not collaborating with anyone in Asia.
Next up after Snoop is a latino to gain access to new fans in latino markets.