Not really more reliable - they required regular servicing, Electromechanical phone switches did - contacts being cleaned, that sort of thing - Modern digital or IP stuff is largely turn it on and stuff it in a closet
> Miniaturization and flexibility come at a cost.
Companies have little to no incentive to update software for older products unless there are lucrative support contracts. This has been the case for decades.
So it basically comes down to security flaws exposed to whatever interfaces it really is connected to.