I have a different question: is leetcode helpful for landing high-paying jobs, or is it a signal that the company is a low-paying company? Because I'm pretty good at the leetcode thing.
Higher level roles and senior roles focus more on system design and offloading more responsibility for you solving their technical stack problems.
Step 0: manage to get an interview
Step 1: do 300 leetcode problems
Step 2: fail ("you're almost there")
Step 3: do 500 problems
Step 4: take interview
Step 5: land $300K job (see salaries on levels.fyi, depends on country and level) and relocate) + tons of benefits, include remote work nowadays
Step 6: Struggle with legacy code, buggy internal tools, stressful performance reviews, strong colleagues who set the bar very high, high turn-over, oncalls. But the money is real, and overall management and colleagues are pragmatic and skilled.
I assume a smart/lucky/fast thinking guy can do with less than 500 problems. I also assume that as these recipe is getting well-known, difficulty of problems is going to increase.
Also not that this work even if you didn't graduate from a top school, even if you don't have significant experience, even if you're an older candidate. In that sense, these companies don't lie on the "equal opportunity" stuff. It's all about how much you're willing to grind these problems.
Other may offer counter opinion, but this was my experience as well as other new recruits.
What if you aren't willing or able to relocate, though?
Many jobs are fully remotable now (tho it varies from almost all of them like Meta, to almost none of them like Apple). Sometimes slightly less money.
I can't generalise to all the teams and companies, but this was my experience, and I've seen some similar profiles around me. I suppose if you really check all the wrong boxes, it may be hard to land an interview, but once you're in the process, you have a shot just like anybody else and it really boils down at how well you do at the leedcode questions. Concerning diversity, interviewers are trained to avoid common biases on gender, age, and recruiters have incentives to interview people from minorities. I would say that if you come from a minority, you are at an advantage and you're more likely to get an interview.
What is clear, is that not everybody graduated from top schools. There are plenty of SWEs coming from developing countries. Older people are more rare. I was hired at 45, and the bar was a bit higher as they wouldn't hire me below a certain level. I've also heard stories of people hired at 55.. so there's hope.
If you're unwilling to relocate, you may be able to remote work from a different country. This depends on the company and the role, and which country you want to remote from, but it's doable.
To me, the main issue with leetcode is that it's not transferable kills. It may be very frustrating to spend 100s of hours doing these problems and not being able to land a job in the end.
I definitely know a lot of Googlers and Xooglers who didn't graduate from top schools. Or at all.
Leetcode is the kind of thing I enjoy.
I'd say it depends on many things. What level are you applying to. And also, how well you perform in situation of stress. And of course, in the end, it's a competition. If the other applicant can solve problems faster than you, they'll get the job and you won't.
For me the hard part wasn't solving the problem, but solving them in 15 minutes. At Google, 2/3 problems I got were hard and not medium. There would be no chance that I solved any of them if I hadn't seen them before.
You can go on LC (I think it requires premium) and see people post similar things (may be biased there). There's an entire category in the problems where you can see what companies have asked certain Qs and their frequency (6 months, 1 year, 3 years, etc).
I myself am starting the LC grind, the only thing I've honestly regretted in my career is not getting a CS degree (mine is in Maths). Never having a solid foundation in DSA makes LC prep painful, also the first time I'm prepping LC in general.
I'm a frontend developer for the last 7ish years and it kinda sucks that I have to do LC to get these jobs. I know some companies are starting to give different tracts for frontend roles but the vast majority still seem to be LC problems.