Well, I thought about building my own, but it's not so easy as you make it seem to get one that is efficient (i.e., not just brute force capacity through size) and easy to use.
- How to make it not look like an animal food barrel in your living room, aka WAF, although I do find that term somewhat demeaning as I get older - I used to not care about such things either when I was in my 20's, but nowadays I do, even if it's just because of the realization that people around me care.
- How to make a mechnism to easily fill it, without spilling. This is related to size - you can have a huge one so that you only have to fill it every few days, but then you'll need to shlepp around buckets or watering cans. If it's smaller, you need a separate tank, which you now have to hook up to the rest.
- How to moisten the wick. It's called a 'wick' because it, well, wicks, of course, but you need a relatively large surface contact area to get lots of water into the wick(s); or you need a pump that will keep vertical 'wicks' wet all the time.
- The fans need to be on the top, and large for minimum noise, but the largest Noctuas are only 20cm. But you need air intake from the bottom, somehow, while still maximizing volume efficiency (i.e., you don't want 75% of the volume of the device to be unused because you can only have water in the lower 25% because of the airflow design).
- You need something that can be cleaned and filled without too much (preferably no) disassembly, and you don't want moving parts like floats or fragile things like measuring water level with metal strips because those will break within a year or two; or faster if you don't have a water softening device in you house.
Overall, I think humidification is a job of proper devices that are part of the indoor climate control system along with heating and cooling, but I don't know of residential systems that combine all, and if they do/would exist, it would be much more expensive than the few 100 at most people want to spend on this, and require extensive plumbing to get installed.