I don't agree with your arguments that hardware wallets undermine one's sovereignty. They are just a specialized tool to aid you sign your transactions more securely. Perhaps you could argue that ten years ago you could get locked into their system but almost all current hardware wallets use the open standards (BIP32, BIP39, output descriptors) so you can easily migrate to any other hardware or software wallet.

The most compelling argument to use them is that they are specialized computers so their attack surface is greatly reduced compared to any general purpose computer. If you're using a general purpose computer you're at greater risk to hardware and software attacks. Setting aside hardware attacks, to securely use a general purpose computer you need to verify the OS and your wallet software each time you use it. All it takes is one time you don't do it. Then you have to hope that no upstream libraries have been poisoned (e.g. XZ backdoor). There's a reason why the Dark Skippy attack was done on a SeedSigner. It's just so much easier to create a modified version and there's no secure boot protection.

Lastly, just to address your point about hardware wallet manufacturers shilling their product and creating FUD. I think a more correct assessment of the situation is that they have identified problems with using generic hardware/software and are providing a solution to remedy that. I haven't ever see them make false claims what they're doing just to sell more devices.