There is no point making up irrelevant scenarios and discussing them, United has been consistently competing for top 4 in the last 7 years.
Yes. Which is terribly underwhelming for a fan base that experienced the SAF years (well, the SAF years after he turned United into a winning machine, obviously).
But it's also "there or thereabouts" from a certain perspective.
Liverpool remained "there or thereabouts" from a certain perspective too, during their barren years between the pre-PL era and...now. In fact, if it weren't for SAF they might have easily won a league or two.
Did Liverpool become
irrelevant at any point between winning the league in '90 and winning it again last season? No, they did not. As evidenced by fan base, revenue, sponsor deals, and so forth - in terms of
money, they lost ground to their rivals (as you'd expect), but they hardly faded into obscurity or lost their ability to compete financially (relatively speaking).
Liverpool's rise in recent seasons isn't the story of a team that went entirely to shite - and then somehow managed to come back from the dead. They were always there, a bit behind - but there. And this obviously has something to do with their status in the game, established by decades of high-profile achievements: huge world wide fan base willing to buy into the "glamour" of the club, the idea that they were a "sleeping giant" (rather than a
dead giant) - and so on.
United and Liverpool are very similar, whether we like to admit it or not. Which is good news in this particular case. We could easily pull off their "sleeping giant" act for years to come, I suspect, without becoming irrelevant - and it wouldn't take more than a few shrewd appointments (and a bit of patience, granted) to bounce back.
Of course, when I say "good news" I have to add that it probably isn't good news for us fans if the Glazers are sitting there, literally banking on precisely this assumption, being content to cash in on the "legend" forever.