Structurally they are similar enough that we can communicate. The discovery would be altering our science, but every attempt to exchange beyond technicalities and niceties is somehow incredibly boring to both sides.
After the initial awe, it would be like, yeah, we know aliens.
Stargate SG-1, S05 E10, “2001”
The Aschen have all the tech that humanity needs to fight the Goa’uld but they are super boring. Also secretly genocidal.