I am looking at whats being said and I can see where FB is coming from.
You say that you took up running a year ago but even with that MPW (be it 50 or 80) your half time doesnt seem to match the effort you're putting in... When I did the very odd bit of running and went to do it more seriously, I went from 3 mile runs to a half marathon in 4 months and had a time of 1h54m... The time may have been quicker if it didnt have 1100ft of climbing in the route... I was only putting in circa 20-25MPW as well for that.
I just followed "Higdons Marathon Novice 1" guide as I had a reasonable 3 mile base to start from and it had me running halfs pretty quickly and in an ok time (I was 33 at the time
)
I really wouldn't put too much thought into my HM time because it wasn't paced optimally, the last miles I started sprint up a bug ass hill and flying past pro-looking people, and felt great afterwards- went out for a big run the next day. I had a really high fever for night straight the week before and when asking on runners world 1/3rd of people said not to run at all, 1/3rd said run slowly for fun, 1/3rd said go all out. I woke up on race morning with a bad cold so decided on the run for fun at an easy pace, that easy pace happened to be close to 8 min mile, once I got to mile 9 it was obvious I had run too slowed so legged it over the last miles.
I ran 13 miles of hilly forest trail back in early May in 1hr50min without any focused training , which promoted me to sign up for a marathon. So looking at that of course my time didnt I rove much despite a summer of training but I don't think that is indicative of anything. I could barley walk for 2 days after that run, now I can run 12+ miles at a much faster, with a far lower heart rate and go out the next day feeling great for a other 8-10 miles.
When scanning through my training logs my long runs used to be at 9:45 a mile for 14-15 miles and I would have a rest day before and after and the subsequent day was shirt and easy. I can now run 20 miles at near 8:30 mile and maintain a lower heart rate, lower breath rate and feel much better the next day. That is a huge improvement AFAIK.intervals are similar, when I started intervals in July I would aim to do the 0.52 miles around a lake in under 4 minutes and do 4 laps, I can now do it in 3min26 and do 6 laps averaging 3:34. Some of my runs have big hills and I used to aim to go 1/3rd of the way before walking, then half, then all the way but slowly, now I can hill train on them and race up them.
Now, I do agree I am running a lot and I'm certainly not following an optimal training plan. I could probably cut my weekly miles and not loose a huge amount if progression. I do 2 8 mile easy runs a week mostly to bump my weekly millage, and 4-5 miles in a gym warm up before doing weights. Some would say they are "toxic" miles . I certainly agree they are the least important and those are the miles I will drop/skip when my schedule needs adjusting. But I still believe they have a small benefit, typically my legs will feel better after those 8 than before (and not just short term).
When I started formulating my plan as well as reading all the books, scientific literature, online plans etc, I asked/browsed around running forums a lot. What came up time and time again was people saying that their marathon times didn't improve until they increased their MPW form 30 to 50 miles, or 40 to 60, or 50 to 70 miles etc. It seemed most people improved up to around 70mpw and beyond that the returns rapidly diminished and injury risk greatly elevated. This is also supported by scientific literature. So that is what I set as a peak weekly millage.
But all of this talk of race time is stupid. I can almost certainly runs a faster marathon next time with 30% less training than this time! That is just the nature of sports and endurance exercise. When you at e a beginner you have so many disadvantages against you, and a lot of it simply comes down to a curated hours on the road, and the only way to get that is to run. If you took the current world record holder for marathon distance and had him sit in a. Chair for 16 weeks and had me run what ever training plan you want he would still beat me by 90 or more minutes. Just like in my half marathon there were a tiny fraction of women faster than me, because biologically they just don't have the same muscular, neural and skeletal systems.