I'd say engineers are at fault for bugs and performance issues, as well as poor UX (not counting what's made to sell you something or collect your data)
I've had to aggressively pitch to execs who've totally ignored the fact that $app is vulnerable. Would result in fines and if we optimized it could be pushed to milk further money offering X feature. I was denied because it's a waste of time, cost and "didn't provide anything for the company".
After finally persuading them and getting the classic response of "Oh!, why didn't you say so" three weeks later was fired for making the company waste money. This wasn't a small company in an industrial park.
Ever since I've turned down jobs that smell like toxicity. You can sort of see the companies stink when you enter reception.