Windows 10 routinely deletes problematic files from peoples computers; it's called "Windows Defender". Most users are happy to let Microsoft delete malware. The reason that propaganda videos aren't detected as malware because none of these companies give a damn about what you're using your computer or your private storage for. It is a ton of extra work for them to run some censorship side business to specifically annoy conspiracy theorists. The reason that YouTube deletes propaganda videos is because nobody will advertise on them. They cost money to store and serve to viewers, but will never generate revenue. Some are so bad that they drive advertisers away from other videos. All this "censorship" is at the behest of advertisers, or fear of backlash from advertisers.

The thing with YouTube is that its greatest power is its greatest weakness. They let anyone in the world serve 4k or 8k videos to an infinite number of users. They find advertisers for your videos and automatically run their ads on your videos, so that you can get cash money from producing them. And, there is a recommendation engine so that viewers can discover your video and channel. With those advantages, come disadvantages -- the service as a whole is called YouTube, and so a bad video on your channel reflects poorly on other channels and the service as a whole. So they have guidelines to protect their success, at the cost of not making all the advantages available to you. That is why there are "guidelines". I am sure if you buy a Google Cloud account and pay for the transfer and storage of your content, and find your own advertisers to fund it, you can host as many conspiracy theory videos as you want and nobody will stop you. But I think you'll find that you make negative money on this proposition.

(Also, I personally paid $200 for Windows 10, so I'm not sure how people are getting it for free.)