The more individual developer stories I look into on Sponsors or Patreon or wherever, the more I see a recurring pattern. The vast majority of developers don't make any significant money. The outliers that do use the platform as a general-purpose payment processor. They take donations, but they also sell things. The line between isn't terribly clear.
The platforms help style all the payments as "donations" or "sponsorships" or "patronage". That avoids harshing the project vibe with overtly commercial overtones that turn off the financially immature and preternaturally entitled. But in reality, they're often really payments for products, services, access, and so on. Some people do simply donate, usually small dollars, and don't receive or care about "perks". Others buy the perks on offer specifically, as a simple exchange. Somewhere in between, people and companies may be inspired by donation-like feelings, but use the benefits to get their payments approved and expensed.
It's hard to draw any broad conclusion from outliers. But it all points to there being strange value in muddying the concept of paying developers with a lot of ambiguity, on both the buy side and the sell side. It's like one of those statues that looks like one thing from one angle, and something completely different from another.