I am 32 years old and run 90mpw but get beaten by 18 year olds on 40mpw

First things first: I assume this is a trollpost. Meaning I don't think you really mean this things, you don't mean it's unfair and you don't give a sh.. about recognition.
But it's pretty much the same here for me. I run 140-150 kilometers per week, run 6 days, 1 day crosstrain. I can't be positive about the mileage of my competitors, but it's safe to say the guys in their 20s don't run as much (I think). I started running early 2020 doing nothing before that, and I'm in my late 30s so I have very low lifetime mileage and I actually have to run this much. I tried with less and the results were pathetic.

Shift perspective, mileage is not everything.

What's their max speed? What is yours? When you are trying to run, for example, a 15:00 pace 5k, are they running at a lower % of their maximum effort than you are?

Yeah totally agree with this. Mileage is important but how you run that mileage matters a lot, too. Maybe you’re overtraining. Maybe you’re going too hard on easy days or threshold days. Maybe you’re not doing the right stuff at the right time. Maybe they’re just more talented. It could be a lot of things. I see this a lot, people absolutely slogging out high mileage with mediocre results. Most of these folks refuse to do things differently. I just wonder how much faster they’d be if they made some changes. Again, not saying that mileage doesn’t matter. It does. But you also have to really listen to your body and find what works.

You aren't guaranteed anything. You don't have much talent as a runner. Who gives a crap?

Don’t cope, stop running so much mileage and find other avenues of meaning and purpose in life.

You have must not run in HS or college, to not realize until age 32, that there are other runners far more talented than you.

Lots of people don't like hearing this, but speed matters A LOT. Just making up numbers for an example. You could, and I've seen it done, take a low/medium mileage middle distance runner, someone who is used to running reps on the track at 5:00 pace and faster, someone capable of a 4:20 mile, and turn them into a respectable 10k or half-marathoner with a modest increase in mileage and tempo volume. Maybe they go and run 72 or 73 for a half—that's believable if you ask me. You will have a lot harder time getting the same results out of someone who can barely crack 5:00 for the mile, no matter how many miles they run. They will always be that much closer to their redline.

If this is a real post, the sadder part is that you have not learned that running is a genetically-limited sport. Hobbs Kessler ran 3:34 off 18 months of serious training.

99.99999999999999% will never run that time even if they 180 years to train.

And aerobic strength matters just as much. If someone does have the genetics to be a strength runner, running 90 mpw is not going to change anything.

The races are run at a fast pace. If you just run long slow mileage, you can't compete. You need race specific efforts as well as work that builds your engine, your power, your aerobic capacity, your lactate threshold. I've done 110-20 mpw for years with little to show for it because I haven't been able to get the workout quality necessary, primarily because of recurrent calf tears. Then when you are optimizing training and recovery, and staying healthy, you can start talking about talent being a divider.

I am 22 and I do the same training as my teammates. My PR is 14:27 yet I have multiple teammates who have run sub 14.

Silly Wabbit, one of the first things you learn is there will always be someone faster than you.

I assume you meant "If someone doesn't have...".

In general, yes, I agree. People like to say speed can barely be trained. I don't entirely buy that. You can absolutely make speed improvements. You'll probably never turn a slowpoke into a sprint star. But you can turn someone kind of fast into someone really fast. Or someone kind of slow into someone kind of fast. One time I witnessed someone go from middling speed in early HS, think 11 mid to high 100m, to 10.3 in college. They put on a lot of muscle in the process. But that kid that can barely break 14 for a 100m will never sniff 10.xx.

With aerobic strength, I think you have more wiggle room. People in general have a bit more capacity for growth in that department. Of course some just have the genetics for it.

Better check that math

Mileage is for losers.

Cope.

Donald Thomas became high jump world champion after 8 months of high jump training (he had been a university basketboll player).

A purely "quality vs quantity" issue. Most of your better known running coaches and writings favor a systematically structured training program. Just going out there and running will only get you to where your are now. And there are plenty on this forum that tout that its all about just running. WRONG. You need to do your homework.

First step is Denial. Good luck on your journey towards Acceptance.

I can crack 15min over 5km but only have 13.8sec 100m speed

Always a brutal experience to run against 18 year olds with at least <12sec speed