That you have to call this approach a mental illness is poor criticism.
macOS doesn’t ship a 32-bit version, because the 64-bit version on every platform is much faster and more secure, and shipping both would be twice the disk space.
(More secure because you can do so many tricks like PAC with those spare bits in every pointer.)
Technical debt is when people make a mess, its perfectly possible to clean that mess without breaking ABIs. Particularly in OS's where the ABIs tend to be decoupled from the underlying code by abstraction layers. For example you can swap the filesystem in use and still maintain the behavior. Linux's syscall ABI has been basically static for decades, its only the userspace layers that don't try and adhear to those levels of compatibility.
PS: We like to give apple all this credit for having a "fast" machine, but the real question should be, if it can't solve the problem I have, does it matter how fast it is? Mac's for the vast majority of the people I see using them are basically trendy chromebooks, where the users are spending 99% of their time in safari. So its probably a good choice for apple if that is the user base they are interested in.
And it only works when your application doesn't have HW requirements that can no longer be met. Or the company in question just doesn't provide drivers anymore.
Frankly, the driver thing is somewhat understandable, but as you point out its easy to bolt software compatibility layers on, why the OS vendor can't manage to make it work well/transparently is a mystery.