This post on Threads lead to a rather sharply worded response from me.
Note: the account holder DOES post some good stuff; I can recommend the account to runners. But..

“Excuse?” I suppose I can interpret that as him talking to someone who WANTS to do a marathon but is trying to talk themselves out of it. And, to be fair, that might apply to a group of people that is larger than the group that I am in.
Yes, I’ve finished the marathon (or beyond) distance 62 times (a few times fewer if you do not count my DNF in the 100)
And, no, I was not good at it. My PR as a runner is 3:33 in 1980, master’s is 3:38 in 2000. I did several as a walker (walking 100 percent of the time) and my last time was in 2019; it took me 6:42 (walker)
No, I am never saying “never again”, but given the tenuous health of my knees (currently tolerating 10 miles fairly well) and lumbar, I am NOT doing a marathon in the foreseeable future. And that is right decision, for ME at my current stage in life. Now, if I drop from 195 lb to, say, 178 lb…who knows? Right now, 10 miles is very comfortable but I’ll need 18-20 miles to feel that way before I start looking. It *could* happen, though I don’t see it as likely.
But here is my point: I did my first marathon when I was 21 and, frankly, I did not know what I was doing. But I was doing 15 miles at 7:40-8 minutes a mile, and could do a 5:30 one mile and a 19:20 3 mile (just at 20 for a 5k) and had run for sports for YEARS. I did not go from “couch to marathon.”
I honestly think that way too many never give their bodies a chance to adjust to running first and end up walk/jogging/shuffling to a 6 hour plus marathon.
And, well, the marathon is hardly the pinnacle of running achievement. For example, a 22 minute 5k is much better accomplishment than a 5 hour marathon.
As an aside, I talked to the young man who fit me for walking shoes. It turns out that he is pretty proud of his sub 2 minute 800, and he SHOULD be. That is harder than people think.