It took me years to internalize this and get over the aversion to studying for these interviews. At the end of the day, many reasonably competent people could do the day-to-day work just fine. Interviews, however, are their own separate thing and without prep, it's quite unlikely to pass the interviews at these tech giants (yes, there are people who have done it, they are the minority). Might as well make peace with it. Personally, I think this is a hell of a feedback loop companies got themselves into, as they all, as far as I can tell, struggle with hiring senior talent, yet are unable to let go of these hazing processes.
I do reserve a certain amount of ire for companies/startups that copy these interview styles without having the same constraints or pipelines. Knocking out a great portion of candidates that would have likely done just fine on the job, because the hiring teams didn't bother to build an interviewee-friendly process boggles the mind, given how desperate many of these companies are to hire.