>>18386175It just becomes infeasible to have travelled for so many days, on so many adventures, with so many companions and not have aged at LEAST a year. The Simpsons works because it's the same little town and the same cast of characters year in, year out. The visuals and setting are timeless and it eventually returns to the status quo whenever they move anywhere or do anything, so the characters are allowed to be ageless as well.
If the Simpsons family took a road trip around the US for months on end, then decided to travel to Europe, then Australia, then Russia, and then on their way to South America casually mentioned that they are all still the same age and not even a year has passed, it would be absolute bullshit. Hell, I'm rewatching some B/W filler right now and Ash literally spent two weeks training a Caterpie to evolve, during their ANNUAL migration, mentions that his Butterfree was released under similar circumstances, and yet he hasn't aged a single year since he let it go.