I think a doser is a must once you get into SPS. A backup temperature controller like an
Inkbird or even a Reef Keeper Lite is also beneficial (stops a run-away heater from destroying your tank). Other than that, I don't see anything that really "needs" automating.
I think cars are a good analogy for this hobby. To some people, like myself, the car I drive is of little importance. My Civic is 8 years old and I jokingly say I want to keep it for another 20 years (although truthfully I'd like to get at least another 10 years out of it if I can... we'll see how that goes). I want it to be reasonably comfortable when I drive and I want my car to be very reliable, but other than that, my car just needs to work. Driving in the car, maintaining the car, and looking at the car bring me very little joy. I want to go to work, see my family, and do fun things. The car I use to get there is not important: it's a means to an end. However, there are some people I know who are car nuts. Their car was very expensive and is kept in pristine shape. It has all the options, bells and whistles. Sure, a car that cost half of what their car did would get them where they need to go. But that's not what's important to them: those people really love cars, and the car they drive is very important.
I look at reef tanks in the same way. I don't care what equipment I use. I don't care how it looks. I don't care if there's a supposed better way to reef than the low-tech way I'm doing it now. My goal is not to have a cabinet full of neat gear, my goal is to have a tank full of healthy fish and corals. The equipment is a means to an end, in other words. For some people, the equipment is incredibly important. It has to do more than just "work," you have to be able to check all your tank stats from any Internet-connected device in the world, even if you spend 99% of your time within a 30 mile radius of the tank. More than just a basic sun rise/sun set, you have to be able to mimic the daylight cycle on any natural reef in the world. Have simple on off timers worked for aquarium lights for decades? Of course they have, but that's not the point: all those bells and whistles that I would never look at are very meaningful for some reefers. Sure, they could get by with less gear and lower-tech setups, but the gear is incredibly important to them, and there's nothing wrong with that.
Neither solution (low tech vs high tech) is best. They both work, and they both have worked for decades. What's important is the one that works for you, and the one that you like.
