I have no idea what prompted Mrs Rollo to ask me when the characters of The Simpsons were born, or even to try to explain the sheer insanity of how time works in that show, but it sent my brain into a series of spirals; gaming out all kinds of conclusions until this conclusion was reached.
There should be a hard reboot.
For the purposes of this hard reboot, I am imagining that the series would begin with a rest date of 2020.
The Simpsons which kind of started in 1987/8 is both the longest-running American sitcom, and the longest-running American scripted primetime television series. The truth is that any TV show which is that long in the tooth, has a tendency to get stale, and it is generally considered that the so called "golden years" of the show were probably between seasons 4 and 10; which was last century. Since then, it appears that even fans of the show think that it is dribbling out towards inevitable irrelevance.
Unlike a soap opera with a rolling cast, or a show like Doctor Who which can recast everyone, The Simpsons appears to be suffering from the fact that there is basically a fixed cast. Every possible story that can be told and arguably should have been told, has already been told by now; to the point where there is even self-parody.
A hard reboot would solve this problem nicely; while retaining continuity.
Before I move on though, here is a review of the in-universe dates of birth of the eponymous nuclear family:
Homer - 12/5/56, age 64
Marge - 1/10/56, age 63
Bart - 1/4/80, age 40
Lisa - 9/5/82, age 38
Maggie - 12/1/89, age 31
What we have here is Homer and Marge, who were both born bang in the middle of the post-war Baby Boom. Bart, Lisa and Maggie who are about the same age as Homer and Marge are/were when the series kind of sets its markers, are all members of Generation Y. All three of them will have grown up in an analogue childhood but due to the coming of the internet, have more or less lived their adult lives in the modern digital world. Probably they will have their own children by now; and they occupy a space which their parents have done in the current series.
This would open up an entirely new range of story lines, and given that Bart, Lisa and Maggie would now have a degree of agency of their own, instead of merely being under the rule of their parents, I think that this would be far more interesting. It also opens the distinct possibility for intergenerational conflict, when you consider real world implications; namely that Bart, Lisa and Maggie will have found navigating the world of work far more difficult.
Probably Homer and Marge are still in the workforce but there is a very real possibility that their children's working careers will have been far more transient. More than likely, Homer will have paid off the mortgage on a single income but their children might not even have ever been paid enough to qualify for a mortgage at all.
There is of course a precedent for this kind of reboot. It has been hinted that the current Dennis the Menace in The Beano, is not the previous one; because his dad is significantly different. This would imply that the current Dennis the Menace is the son of the previous Dennis the Menace.
Star Trek: The Next Generation appears to be explicity set 100 years after the first TV series ended; taking place in 2369 as opposed to 2269 (which itself was 300 years in the future).
There are of course other issues which could be explored. As the comedian Hari Kondabolu quite rightly pointed out in the documentary The Problem with Apu, Apu is something of a very blunt racial stereotype. For comedic effect, Apu was blessed with a set of octuplets; which if they were born on 23rd Nov 1999, would be 19 years old. I would imagine that all eight Nahasapeemapetilon children, would have that quality that practically every second generation person has, in that they are even more of the nationality of their country than other generations. I think that it's true that for people who migrate to Britain, that their children are the most British of all, that the children of immigrants to Australia are the most Australian of all, and that the Nahasapeemapetilon children would be the most exact representation of what 2020 American would be.
I expect that in the 2020 reboot, that the town of Springfield, which seems almost exlusively yellow in 1987/8 would be far more diverse. There would almost certainly be space for an entire slew of cast members who we have never seen before; since the Simpsons itself is a show which has an ensemble cast of probably more than a thousand by now.
We would learn that someone like Kent Brockman in 2020 who would now be aged 80, would be an absolute titan of the world of journalism; of the kind of ilk of say, Mark Shields; that the squeaky voiced teen Jeremy Freedman would be 46 and still squeaky voiced; and that Bart and Lisa's friends will have basically amounted to where their destinies will have taken them. Of course this has the effect that Abe Simpson born 1907, and Charles Montgomery Burns born 1886, are both dead.
But of course, 'should' does not necessarily mean 'will'. The Simpsons' home in the United States is on Fox. As a commercial broadcaster, they aren't exactly inclined to want to fiddle with the show that turned them from "the little network that could" into "the little network that could not be ignored."
The show should almost absolutely and obviously be rebooted but I just don't think that that's likely.