My experience doesn't support your claim. Solid state has been pretty solid for me.The older they get...the more they fail
Devices that are subject to the vagaries of having to share networks with computers and other bad influences aren't likely to be more reliable.
Then there's the whole idea of trying to get a broadband Service Level Agreement (SLA) versus a phone SLA. At my address, the broadband providers laughed in my face when I mentioned SLAs. If your provider isn't willing to back their service, it probably isn't as good as the service that is guaranteed.