How is it their fault their only rival AMD failed to make a competitive product?

Not collapse, but certainly cut down to size. AMD has a golden opportunity here, now that the anticonsumer crap Nvidia has been pulling has culminated with the ludicrously expensive RTX cards, which bring only a mild boost in performance, and a technology not ready for prime time. I hope AMD take it. There's a possibility Intel will enter this market as well. The more competitors, the merrier.

Maybe if there was more competition, but as is we need them.

NO. On Amazon, the 1080 Ti is selling for around $1000. This is the only place where the prices are reasonable