Wasn't this kinda inevitable? When I was little a marathon was considered a monumental athletic performance achieved by few. Nowadays it's like everyone who has ever put a pair of trainers on has "run" a marathon (completed would be more accurate, because many people walk a significant part of it). Yeah, I know, I know, gatekeeping is not cool etc. etc.

Meanwhile, the world record marathon time must be reaching its irreducible minimum.

It seems to me like more and more people are now pushing distance to set themselves apart from everyone else. If you say "I ran a 2:30 marathon", most people won't know if it's impressive or not. If you say "I ran 10 marathons, backwards, while juggling 10 pineapples" suddenly people are interested.