In many cases, you'll end up making something that works using simple relays way more complex, so you'll still need some kind of technician to troubleshoot the equipment when it fails. The "advances" in equipment technology is mostly for sales brochures but in many cases the increased complexity creates more failure points and simply requires a different type of technician to troubleshoot.

I'm talking about things like PEX, which drastically simplify and reduce the time needed to plumb a house. The construction industry as a whole seems to be making a huge investment in time-saving innovations.