What is the point of the multiverse if not only to be able to continue making movies of the same storylines?

If one movie can nullify another, why should one see any of these movies and not wait until they promise it is the final one?

Stopped watching after about 45 min so it may have gotten better after that. I have only stopped seeing a movie maybe 3 or 4 times so this movie is exceptionally unwatchable.

The sad part is that I used to really like the MCU. The multiverse seemed like a bit of stretch but up until this movie it felt OK, even if I never liked the concept. This movie killed the enchanting MCU for me.