Potentially valid reason why they don't show us the biologics

Firstly, my position is to spill ALL the beans. These warmongers behind the scenes are gonna get us all killed with these secrecy "d*ck swinging" contests with other nations.

That being said, assuming it's true that:

1. We have recovered crafts, multiple types

2. Biologics came with some of those crafts, multiple species

3. The different species have different levels of advancement compared to us. Some species are hundreds of years ahead, some thousands or even millions of years ahead.

4. Other nations, some hostile, are also experiencing 1-3.

5. There is a reverse engineering race, with cold war style "f**k f**k games" ongoing between the US and those other nations, mainly China.

They are afraid that by telling us peons descriptions or showing us the bodies of the biologics, that implicitly also tells China the level of technology we're working on. Different species have different levels of technology, right? They want China to have a huge unknown variable on what level of tech we have recovered, and showing us the bodies also might tip them off to the tech level we've recovered.

Imagine if the most advanced species had only been here ONCE, and that happened to be in China, which they recovered. But the US does NOT have that species/craft. For hypothetical puroses, we'll call them the "Squidwards." Billions of years advanced to us. China is actively working on it and has had SOME limited success on technology only the Squidwards have been known to possess.

The Squidwards seem to have technology the Greys, Reptilians, Nordics, Mantids, Spongebobs, Patricks, and humans couldn't dream of. If we say, "ok yeah, here's ALL the biologics we have" and that list does NOT include any Squidwards, China can safely assume they can do whatever they want, and we can't do anything about it. They've also got the other species we have along with their craft, but the Squidwards, their tech is China's ace in the hole.