I dunno... I'm willing to entertain the idea that COVID-19 was engineered, possibly even intentionally released as well. But given what we know and have seen so far I give the former a lower probability and the latter a very low one. These things DO come up in nature... not every day, but it happens.

Also, the theory of people having better immune systems today making it much harder to spread doesn't really make sense. It may appreciably help the survival rate and recovery time, but sanitation and personal habits make much more of a difference in the spread of a virus than the strength of the immune system. And given how fast it's spreading in metropolitan South Korea where sanitation is usually on par with the US and Canada, thinking it can't spread widely there seems a dangerous assumption.

Here in Mongolia I guess there's one guy getting a little traction who theorizes it was developed by the US gov't and intentionally released in China to cripple its rise. I don't doubt there are individuals in the US gov't sick enough to entertain the thought, but the difficulty in keeping such a thing truly secret and especially the potential damage it can inflict to the US and themselves makes it very unlikely in my mind. Even having a secret vaccine ready to go ignores the possibility of mutations that render it totally or partly ineffective.