> [Synology] comes with dedicated Time Machine support
Your umbrance is with Synology, not Apple.
Apple raised security default configurations in Tahoe. That led to a config breakage with NAS devices which rely on relaxed security configurations.
I agree Apple should publish a technical note / changelog of config changes such as this one, but Apple has never implied to users they'd carry a support burden for any/all third-party hardware vendors. To the contrary, they've notified users that you're meant to consult with your NAS vendor for configuration steps:
> Check the documentation of your NAS device for help setting it up for use with Time Machine
I wasn't even assigning blame, did you mean to reply to someone else?
I was just replying to your point that a Synology NAS "is not what most users would consider 'consumer technology.'" It's firmly in the consumer technology category.