I suspect you're right that most users wouldn't pay, but I've gone to Red Hat's website many times over the years looking for a package that suits me and there's nothing. There's a segment of at least one (me) where they're missing out on some money for doing no additional engineering work.
I can get the workstation offering for $299. And then I can support free-as-in-libre software, I can run the same system my customers are running in production, and I get support that's probably better than Microsoft's. I don't really know what device issues I'm going to run into, though, and in my experience it either works or it doesn't - if I have a new wireless device they don't support, I'm under no illusion that my $300 next year will be the difference between them supporting it or not.
So maybe I'll get the self-supported option. But that's kinda steep - over half the cost of full support. Especially when one way to be confident about device issues is to go install the community distro (Fedora) for free and see if an old release works. If it doesn't, I'm not betting on Red Hat. If it does work... do I want to start this whole process over again, or do I just want to get to work.
Well here's another deal breaker: if I'm trying to run the same distro my customer's use in production, I'll have lots of virtual guests. No can do: my workstation license only permits 1. Let me get the server license and just install KDE myself. The self-support option only allows physical hosts. Let me get the next tier up. Now I'm up to $800 a year, and I, as a developer of software for Linux, am going to have a very unusual use case for them, I think. Should I commit $800 for 1 year of this? Does the server edition run KDE well? I doubt many people are trying that. Now I'm too nervous to cough up $800 knowing it only lasts a year anyway.
I could see myself buying a Lenovo laptop with Red Hat pre-installed and skip this, but I would want to be able to run more than 1 virtual guest with the same system - I'm not sure if Lenovo customers get special terms. Or... I can just buy a laptop I think is better from System76 and use Pop! OS. As long as there's something resembling CentOS or Scientific Linux or Rocky Linux for virtual guests, I can get close enough to my customer's production distro that this is still by far the most attractive option.