system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is Google Chrome so unfriendly to Flash and Unity? What downsides do these programs have?
gpt
The entire tech industry is hostile towards Flash, that is not a Google specific thing. This is partly due to Flash being a resource hog, and partly due to the fact that serious security vulnerabilities seems to be discovered in it practically on a monthly (sometimes weekly) basis.

Flash became such a prominent plugin mostly because there were no real alternatives for video playback back in the day, now that HTML5 has built in support for video playback it has become a lot less essential than it used to be.

As far as the Unity Player is concerned that was never directly targeted by Chrome. It stopped being compatible with chrome due to the fact that it uses the NPAPI extension interface. Which Google dropped support for due to it being an old and complex standard that they felt caused more issues than it was worth in terms of stability, security and speed.