It's a tale as old as time that developers, particularly junior developers, are convinced they could "slap together something in one weekend" that would replace expensive SAAS software and "just do the parts of it we actually use". Unfortunately, the same arguments against those devs regular-coding a bespoke replacement apply to them vibe-coding a bespoke replacement: management simply doesn't want to be responsible for it. I didn't understand it before I was in management either, but now that I'm in management I 100% get it.