To the contrary. Time Machine is for consumers. Most people use it either with an external hard drive (good for iMacs that stay in one place) or a NAS (good for MacBooks). Apple even sold the AirPort Time Capsule at one point. Since that was discontinued, Synology NAS is the main consumer-friendly alternative. It comes with dedicated Time Machine support. It's supposed to be easy setup and forget. That's the whole point of using Synology instead of alternatives that require more technical expertise, that aren't designed for Time Machine support straight out of the box.
> [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
https://support.apple.com/en-us/102423