Whether born of sincerity or expediency or some combination of the two, the alliances have been central to the pop takeover by Drake and Ms. Swift, stars who sprang from outsider genres who now enjoy both mainstream and critical acclaim. Seeing Drake and Ms. Swift pal around widely is no surprise: Accessibility and intimacy are central to both of them. They are simpatico songwriters, vividly autobiographical and strikingly vulnerable. And both have managed to display a kind of everyone-welcome catholicism, allowing others in without ever giving up the steering wheel.

How these bonds manifest in their lives and careers, though, is very different. Drake is one of the savviest collaborators in hip-hop and has made a habit of identifying young talents early and bringing them into his orbit. The benefits flow both ways — the rising artist gets a valuable co-signer and, often, a breakout hit; Drake gets a splash of youthful energy and credit for bringing an obscure idea into the mainstream. For Ms. Swift, her recent alliances have seemed more personal than professional, insomuch as a hair’s-width space between those two can be distinguished. They’re different approaches, but both serve the brand.

They’re starting to falter, too, though — for many reasons. Drake and Ms. Swift are pop’s reigning titans, scrutinized heavily; their habits, repeated over time, can begin to appear premeditated. And friendship, as strategies go, might have peaked. The approach has been perfectly suited to the social media age, where online worth is measured in likes and favorites, where narratives are curated via envy-inducing Instagram posts and where collaboration is just a direct message away.

But too much positivity can begin to chafe. Public friendship requires a tremendous amount of good will, or perceived mutual self-interest. It demands that everyone stick to the script — which is why Meek Mill’s allegations were so bracing.