I did one in my mid 40s (about 10 years ago). I went from non-runner to marathon in 18 months and crossed the finishing line in just over 3 hours 47 minutes.
There were a lot of physical factors involved: not being overweight at the start of the training, having been a "walker" my entire life and so having resilient joints and good "form" as a basis, training purposefully for the event (i.e. no junk miles), and plenty of cross training to save my joints and make me lighter on my feet.
Mentality was also a major factor: I found my 10km practice races to be sheer torture and one of my half marathons to be possibly the most painful event of my life (child birth included!), but distances over 30km sort of "clicked" with me. It was like being on a high: I could sustain a good pace but also disassociate myself from the pain, meaning that I didn't get overwhelmed by it, as in shorter distances. This made the running fun and, over time, I found that I would sometimes choose to run places simply as a mode of transport.
So I suppose I think that, disabilities and injuries aside, it is possible for anyone - but that some will have it easier than other, depending on whether that is "your" distance.
I'm actually just toying with trying to run another. But 10+ years later and with 15kg+ excess weight, it's hard to know if I even dare try 😂 and where exactly to start .