> I'm not sure about data collecting though. This developer's uBlock is famous to make external connection in background

What is this nonsense? Stick to facts/evidences and stop spreading disinformation.

uMatrix and uBlock Origin connects only to download assets used (filter lists, hosts files), and you have full control over this. I know of no content blocker in the same class as uBlock Origin which do not need to regularly download filter lists for their proper functioning, so you have to be trolling to claim that I am "famous" for what is the expected behavior.

Privacy policy is here:
uBO: https://github.com/gorhill/uBlock/wiki/Privacy-policy
uMatrix: https://github.com/gorhill/uMatrix/wiki/Privacy-policy

If you do not like it, just don't use the extension, and refrain from spreading disinformation.