It seems to be a bad idea to buy commercial NAS devices, because eventually, every device would go end of life. Better build a DIY device with an open firmware.
But thinking again, this kind of approach wouldn't be applicable to typical ordinary people. Then I guess the next better thing would be to force NAS devices to stop accepting Internet-facing connections after their support period ends. Every device has a defined lifespan which dictates how long it can work without sacrificing quality. As a device dealing with important data, NASs should be given higher restrictions.
But thinking again, this kind of approach wouldn't be applicable to typical ordinary people. Then I guess the next better thing would be to force NAS devices to stop accepting Internet-facing connections after their support period ends. Every device has a defined lifespan which dictates how long it can work without sacrificing quality. As a device dealing with important data, NASs should be given higher restrictions.