From my experience, most businesses (or at least the developers working for them) actually would like to donate or pay for support on the OSS projects they rely on. The problem, at least from my experience, is that it is hard to do so due to legislation, compliance, etc.
Example: I once convinced my employer to donate to some open source projects we relied on. They did, then few months later they got slapped on the wrist by the authorities for not being able to prove where these overseas payments were going to, and that these payments weren't used for funding terrorist activities.
Similarly, I used to contribute to an OSS project, we did get asked by some corps to do paid work like bug fixes or features. The problem was that they required invoices in order for them to be allowed to pay us, so we needed to register as a company, get a tax number, etc. I was a freelancer at the time, so I offered to use my business registration to be able to invoice, then split the profit amongst the contributors. Then the very first paying 'customer' immediately hit us with a 20-page vendor assessment form asking about my SOC2 or ISO27001 certifications, data security policies, background checks of my 'employees' etc. Then I got confronted by my accountant that distributing the payment amongst other people would be seen as disguised wages and could get me into serious legal problems.
Granted, this was some years ago, things have gotten better now with initiatives as Github Sponsors, KoFi and Patreon. But at the same time legislation has gotten more restrictive, doing business with large corps is difficult, expensive and very time consuming. It's not worth it for most OSS maintainers, and similarly it isn't worth the legal headache for the large corps to make these kind of donations.