I said guess, not bet.
And I do have the Fermi Paradox on my side.
To anyone who says I’m wrong I say:
Show me the aliens!
Similarly Frank Tipler limited his claim, "Extraterrestrial intelligent beings do not exist" (Royal Astronomical Society, Quarterly Journal, Vol. 21, Sept. 1980, p. 267-281) to the Milky Way galaxy.
An answer to the question of whether the Milky Way galaxy is the only one with extraterrestrial intelligent beings will include the same factors which likely limit the number of Milky Way planets with intelligent beings to approximately one.
In addition there are also the other factors, such as whether there are unique galactic features necessary for intelligent life (regardless of whether they have the capability of intergalactic travel) to exist within that galaxy, which are only found in such special galaxies as the Milky Way, e.g., the size and shape of the galaxy, the size and activity of the galactic center black hole, the abundance and distribution of other black holes within the galaxy, the frequency of collisions with other galaxies, the amount of dark matter present.
I think you are right, there is nothing intelligent out there. (Sometimes, that includes us.)