Fram variously rates them for 20k and 25k miles. I/we live in an extraordinarily mild climate and time is just not a factor, practically.
That said, in the past the car was doing 15k to 20k miles a year, so I was leaving them on 1.5 years max. Covid and new driver/low miles changed that. I had previously done 2x 20k+ miles intervals with them and I knew they had no issues doing that/doing what Fram said they would. My goal is 3x 7.5k oil changes for 21.5k total miles, but I forgot and this did get a little long vs. my intention. It had Rotella Gas Truck 5w-30 in it the last two fills, so I didn’t worry about the oil going over a little or the filter, either.
I agree with you, that for those of who grew up tossing a filter every 3k miles, it sounds insane. But the design and technology makes it possible. It took me a little while to get used to the idea initially. I didn’t start doing the long interval until I had seen others do it, and had cut them open and shown the results.