The conclusion of the research is that solution energy efficient and cheaper. Smart bulbs are nice, but they solve neither of the issues mentioned. They need to be powered on all the time and you still need the switches either way, unless you design your home to be solely smartphone controlled but nobody does that.
I do self-host some services but it bugs me that a lot of articles that talk about costs do not factor in a lot of additional costs. Drives for NAS need replacement. Running NUCs means quite an energy draw compared to most ARM based SBCs.