There are plenty of tech companies not using dark patterns (I used to work for one). Granted Amazon employees might not be able to get paid as much elsewhere, but that's the choice you make.
I have worked for 5 companies in my 15 years career. One of that company was ecommerce consulting firm which dealt with a lot of mom-n-pop ecommerce stores. Let me tell you not a single one of them was willing to give up any dark patterns if that meant losing revenues. Unless you are working on non-revenue generating product like internal dashboard, it is all about get sales anyway possible.
I am sure there are ethical companies, I see many of them mentioned here, started by readers of this forum, but what percentage are those. Imo, they are less than 1%.