You can, however, be thunderstruck.
Anyway, Marvel’s multiverse is every bit as convoluted as DC’s ever was - worse, in fact, since time travel canonically creates new universes, one with events changed by the time traveller, one where they’re not… So you get many universes with very minor changes - for example, Earths 715 (home of Thundra), and 8809 (home of Lyra…the daughter of Thundra, by the Hulk).
Except when it doesn’t, so you get things like Age of Apocalypse, House of M, or 1602 overwriting 616, then becoming proper universes in their own right after 616 is restored.
Most of their major continuities have had major multiversal interaction.
Earth-616 (the main universe) has interacted with the multiverse majorly in Fantastic Four, Excalibur, Exiles (which tied in strongly with the X-Men for a while) and Avengers.
Earth-715 (the home of the original Squadron Supreme), save for the 12 issue LS from the 80s, EVERY appearance has been multiversal - their first several appearances were conflicts/teamups with the Avengers, as was their first post-LS appearance, and their most recent appearance was when Power Princess was recruited into the Exiles.
Earth-1610 (Ultimate Universe) has interacted with the multiverse primarily in Ultimate Fantastic Four (zombies and Godwar arcs), though also in the Ultimate Power crossover with Earth-31916 (Supreme Power), which resulted in 31916 gaining Ultimate Nick Fury, and 1610 gaining Zarda.
Which was the only major multiversal interaction for 31916, but it was a nail in the coffin for a universe whose only title was already limping along.
Marvel Zombies (initial shown reality Earth-2149) is entirely multiversal, as is Exiles. (Marvel Zombies is also a time-loop - Earth-2149 was infected by the Sentry of Earth-Z, which was infected by the Giant Man and Wolverine of Earth-2149.)
Nemo, have you seen the current state of the Ultimate Universe - the Mutant side of the universe (always a big deal) has been decimated, as have the interesting villains (Doom and Magneto are both dead), the Thing has become a coldblooded murderer (he crushed Doom’s head with his bare hands)… They’ve been making full use of the fact that the Ultimate Universe will never be anywhere near the main continuity.