Evolution on this planet would allow reptilians to exist
I never understood peoples fascination with dinosaurs/ancient reptiles until I heard about the thought from multiple people, that reptilians aren't necessarily ETs, and are actually the natives of this world that were here long before us, with the evolutionary explanation for why lizards not having a combination of human like hands and bipedal legs for running, walking and performing other task not being consistent. Starting off with what's comparable to a lizard, the common ancestor type of all mammals were small rat like creatures, and the common ancestor of the ape family is a small monkey like creature, which goes to show how far the lineage has come and how it can drastically change, and that walking and running and having thumbs for complex manipulation, tool use and carrying is evolutionarily superior due to their obviously being more humans on this earth than any other ape, not saying being bipedal and having human like hands would AUTomatically give them the overall human like intelligence and cognitive abilities, but it was surely lead up to that. As for if those two things would benefit lizards and not hinder their survival it certainly would, in the same ways they benifeted humans and led to them out-populating other apes, so those two things aren't an advantage exclusive to mammals or primates. Overall, reptilians existing doesn't go against evolution, and it specifically taking place on this planet, with this thought of reptilians being native actually adding up with the supposed war between them and other NHIs.