Useful for refreshing concepts I'd learnt/coded at Uni, 20 years ago and not used since ... which isn't as snarky as it sounds.
Basically with a bit of drilling, a competent programmer should be able to get the hang of those questions, and maybe the fact you can get competent at doing tricky, niche things is a useful indicator.
I wouldn't say doing leetcode would in anyway make you better at writing clean, well structured code, which is what we typically interview for in non FAANG. Probably does help sharpen your cracking out gnarly inner loop type coding skills i.e. better at writing a difficult function, doesn't do anything for how you would write the rest of the program.
Basically with a bit of drilling, a competent programmer should be able to get the hang of those questions, and maybe the fact you can get competent at doing tricky, niche things is a useful indicator.
I wouldn't say doing leetcode would in anyway make you better at writing clean, well structured code, which is what we typically interview for in non FAANG. Probably does help sharpen your cracking out gnarly inner loop type coding skills i.e. better at writing a difficult function, doesn't do anything for how you would write the rest of the program.