There are some very cheap ones about for people who feel as you do.
A lot of people actually buy cheap ones too, and when they find out that it leaks light everywhere, provides uneven illumination, that the diffusion materials are the wrong colour/and or are too thin, and that the cheap design doesn't allow light to be feathered and doesn't allow a honeycomb to be fitted, they throw it away and by the one that they should have bought in the first place
As someone who has been to the factories and actually seen them being made, personally I think that the decent ones are good value for money - generally - although of course there are some premium brands where you're paying an inflated price for the logo printed on it, but then that applies to all products, e.g. fashion, too.
Many years ago, I bought a Chimera, it cost me a small fortune but it was worth it because I used it primarily for fashion shots, where the main function of a softbox is to make cheap clothes look expensive

Chimera used to be (and maybe still is) the best of the best, after all they were the people who invented fabric softboxes in the first place. Good brands from other suppliers (no, I'm not specifically talking about just Lencarta, Bowens are just as good and come from the same factory) are basically based on the Chimera design and with what are hopefully improvements. The cheap ones however tend to be copies of copies of copies, made by people who have never actually used a softbox and who don't know or care about the consequences of taking shortcuts in production and using inferior materials,