What do you think that some sites are blocked eg Netflix?

I have often heard that some things are blocked because there are too many people at the moment. Use Netflix.

Some games like Roblox too

In Roblox Game Chat there have also been messages that messages are arriving late because there's a problem.

The network is overloaded.

YouTube / Amazon has reduced its quality to SD (420p) by default.

Netflix has reduced its bit rate.

It is clear that the services and networks are completely overloaded if everyone can do nothing else.