When I was at university a lot of people studied hard for somewhat bullshit exams that had little relevance to the work they we’re expecting to be doing for the rest of their lives. And people paid the university for the privilege of getting to take those exams. The purpose of this studying was achieving good grades and the value of these grades was an increased expected value for lifetime earnings. But this value is probably lower than naively looking at statistics would suggest: ambitious, hardworking, or clever students were more likely to do well in exams and those people would likely do well later in life too even if they had food poisoning and failed their exams.
In comparison, it seems to me that job interviewing costs a lot less than getting a degree and the payoff is potentially larger, more direct, and more immediate. It seems that the pain of studying and practicing bullshit leetcode questions is outweighed by the benefit of, say, a 50% pay rise or equivalent quality of life improvement, and I don’t think a moral stance against leetcode is strong enough to justify turning down such opportunities.
But maybe you feel more strongly about this moral position than me. Or maybe you are one of those competent people who can’t do well at this sort of interview even with studying and practice. Certainly such people exist.