Yu are mistaken in assuming businesses want better experiences for everyone, including workflows that may lose them revenue (like cancelations).
The friction is intentional and part of a wider dark pattern strategy employed for "retention" - even Apple does this when one tries to get them to stop an unexpected recurring Apple Music subscription that only shows on ones credit card and nowhere else (apple.com or the Music app). The support number is not provided on amy of the support pages, and ine has to get their bank to stop the outgoing payments. Guess how I know this...
In light of this, I'll gladly take any client-side agent assistance I can get to make to reduce my cognitive burden; the "hold for me" emulates the support agent calling you as you described. , and the experience is more important than implementation details.