Wow what a waste of a pi I do something similar with an esp32 with a relay board for about 5 bucks, that never needs resetting and is integrated with Alexa Google assistant etc all through home assistant which is really the ultimate goal for these type of applications.
I'm not sure the point of the article was this was the easiest best method. SmartThings and even the Garage door makers have systems that can solve these issues too. Sometimes it's just about a Geeky project you can do, sometimes its just a learning experience.
For example the Picade. You could make your own, and save quite a bit of money. However in my case, I picked up one up, assembled it with my son in an afternoon, he had fun, and learned some things, had a good time. I throw this in the same catagory. My garage door is already monitor and controlled by my alarm system. However we could grab a rasberry Pi out of the cabinet, magnets and switches I already have and make a project out of it (wouldn't be permanent but still educational). Just my thoughts.