"Projectors lack the image quality compared to good TVs and monitors, and they’re pretty needy"
It can cost more to get quality out of a projector in some use cases. The room and screen are part of the optical design, but people want it to all be the projector's job which makes things harder. Especially since many of them are trying to replace a full size LCD with a tiny one, a very bright light, and an aspheric lens, and then project onto a matte white wall instead of a fancy retroreflective surface
I got a $45 1080p projector from amazon which was made to mimic the samsung freestyle, those round projectors that can project forwards or upwards. It's clearly a very basic model, with no optical trapezoid adjustment or zoom. But compared to an equal price LCD TV which would be small and probably kind of uneven, it's great as long as you can dim the lights in the room and you have a flat wall or ceiling without strong texture to aim it at. It's easy to use, just plug in power and either a usb drive with movies or a hdmi either from your device or a streaming stick. I use a chromecast so that I can cast from my phone screen. Some have wifi built in using an old android version but I avoided them figuring it would not perform as well.
The middle range home use case (which you are kind of referring to by saying "good" instead of excellent or mediocre) is where projectors don't do as well; getting beyond a certain quality in projectors costs a lot more, and in that price range you can get a large enough plain screen to be satisfied. A way a projector can justify the price is if it does something that a fixed screen wouldn't - like be huge or retract the screen up to the ceiling when not in use. But they can definitely do well on quality if you spend enough; think of movie theaters for example. In fact a lot of the "problems" with projectors are all about the comprimises we've made. A good projector can be in focus from edge to edge, but only if the installation is suitable - if the screen is not well aligned and the throw distance is ultra short, the focal plane is going to be too thin to work.
