How do Governments spy on people?

We can create a reasonably good profile of a person based upon his / her browsing history, social media interactions, searches made, etc. Companies like Google, Facebook, etc., have this profile for every user. This profile can create customized ads for the user, e.g., If a woman searches for pregnancy-related information, she starts to see ads of baby products. Till now, the whole busniess plan seems OK.

The problem is that Governemnt can arm-twist big social media companies, thus violating the privacy of individuals, e.g.,

• Let say the Government wants to know who are the anti-vaxxers. Now a company like Google can create three lists: C - People who are Pro-Vaccine or neutral, A - People writing/creating information about harm caused by vaccines, B - People circulating the information created by A category. The government doesn't have the resources to pursue every one but typically more than 80% of people are category C and less than 1% of people are category A. Now, the government can go after people in category A.
• Let say the Indian government wants a list of people who are anti-Modi. Now a company like Facebook can create three lists: C - People who are neutral/pro-Modi, B - People who circulate Anti-Modi information, A - People who write/create original articles/videos that are anti-Modi. Most Indians are in category C. Less than 1% of people are in category A. So now the government can after category A people. Once they are suppressed, most of the anti-Modi information stops circulating.

How to protect privacy in this environment?
Use two identities: one for normal work and one for politically sensitive work. We can use our normal browser for usual office work. For sensitive work, use VPN, a separate browser, and a separate email. E.g, I have two emails.

1. One email is for the office work that I get paid for. I don't use any VPN for this work. I use Google to search for any information. I do all my work-related social media interactions here. This is my open identity.
2. For my private work, I use Brave browser, ProtonVPN, and separate email. I use the DuckDuckGo search engine. I do all my social media interactions in this Brave browser. This is my secret identity.

My two identities are separate and can't be linked easily. In my open identity, I am a politically neutral or politically uninterested. In my secret identity, I am an anarchist and a nightmare for any government.