At the time I would have loved to see them re-form. Now I'm grateful that they never did. I recall the growing excitement in 1976 when Paul, despite riding high with Wings, speculated favourably to the press about a reunion. Ringo was up for it came the next report. John then climbed aboard with some very promising why not?/keep the door open comments. I remember the UK tabloids were in a frenzy. It all hinged on Harrison. The Daily Mirror were first (I think) with the headline "George says Yeah! Yeah! Yeah!" (the exact words are still burned into my brain). The strapline was, I think "He's ready and waiting for the big get together"..... and then..... nothing. Such a damp squib. But like I say, overall that's no bad thing. All four fabs blew hot and cold over this at one time or another during the 1970s. But as Paul famously said: "You can't re-heat a souffle". And I recall John at one point weighing in with "The world would be so disappointed with four rusty old men".
I think they would have improved the 70s (despite their absence, still for me the best decade on so many levels, especially music) but I doubt the 70s would have improved them. John's idea of simply putting a personal playlist together by cherry-picking your favourites from four separate, patchy catalogues works for me. After all, personal appearances and genuinely combined full group efforts were fading even by 1968.
I agree with Moog that to have witnessed them lamely fizzle out over a prolongued decline would have been awful and would have undoubtedly diluted the legend. And I suspect that is what would have happened, so with hindsight I'm thankful the split occurred when it did. I can still therefore astound younger music fans by reminding them that The Beatles broke up before any of the four members had reached their thirties. Astonishing when you think about it. The 60s were so lucky to be "their" decade.