BIMI, as misguided as it is, does aim to solve this by tying registration to insanely high prices and government-registered trademark verification. You would have a hard time registering the Stripe trademark nowadays in a way that would get you a BIMI certificate for that name/logo.

https://www.thesslstore.com/resources/bimi-certificate-cost-...

But I'm glad that it hasn't caught on as strongly-expected by the public (or even commonly used). Big brands shouldn't be able to buy their way into inbox placement in ways that smaller companies can't replicate.