The threat of losing years of history that longtime readers have invested in, financially and emotionally, is a way of making them feel the weight of the stakes that the characters are dealing with: Readers don’t want this universe to end as much as the heroes don’t.
This is the root of why Hickmans’ Avengers run is working, for me at least. More than being grand in scale and epic, (which is what we want with the Avengers, and team books in general) is the stakes that are being played. No one wants a reboot, and the New Avengers don’t want their world to end.
At least, no one in the internet wants a reboot.