Right because its not actually about age verification or protecting kids. Its about mass surveillance and dominance.

The day ad block stops working is the day I stop using sites with ads

Depends on the field. I did not need a LinkedIn, however often you need to have an in. Knowing one person at the company can be a big advantage and unfortunately LinkedIn can be the only way in some fields. If not having a LinkedIn is something you value more than a specific job then I wouldnt give that up.