The simulation hypothesis is, sadly, perhaps the only self-consistent solution to the Fermi Paradox, one that doesn't require very unlikely propositions.

https://www.exratione.com/2015/05/the-cosmological-noocene/

All of the other suggestions require all intelligent life without any exceptions in our past light cone to behave in a consistent way, i.e. fail to build obvious megastructures, fail to come calling, etc, so as to leave everything with the appearance of being natural. The Fermi Paradox is more the Wilderness Paradox in nature. Given that a tiny faction within any sufficiently advanced civilization could on their own generate self-replicated probes that converts the observable universe to computronium, and that some portion of humanity will do that if not stopped, and that we appear in no way to have exceptional origins or be in an unusual region, that really suggests there is something fundamental that we don't yet understand.