[RetroTechie]

We simply don't kow.

On a scale of probable -> less probable, you have:

Self-organizing chemicals -> replication -> evolution -> multi-cellular life -> creatures that move around -> intelligent life -> use of tools -> basic technology like wheels, steam engine -> industrialization -> advanced tech -> automation -> space faring -> capable of interstellar travel -> capable of intergalactic travel. Powered by energy sources of increasing complexity/sophistication & scale.

This whole evolution requires a stable environment. Dinosaur-killing asteroid & it's back to square 1. Also (for example) how would intelligent life on a waterworld (which basically excludes electronics as we know it) become space-faring?

So it's not unlogical to expect that microbial life could be 'everywhere', tool-using intelligent creatures are rare, and interstellar-capable civilizations are so few & far between that (on average) they're just too distant in space or time.

Doesn't matter who visits who if neither party can cross the ocean in between.