It's always best to buy/sell Bitcoin in person. Most exchanges are not really trustworthy - either they get ''hacked'' and/or they collect and distribute your private information to everyone asking for it or paying enough.
People who are sending copies of their passports to such exchanges are crazy imho. Identity theft and full-spectrum surveillance are only a matter of time. It's sad.
What you said is true about giving personal details and documents to exchanges are risky but even when you are dealing with bitcoin in person is also full of risky more then dealing in exchanges. So it is much preferred to use the local exchanges who are dealing without having to give personal details and documents.
Earning Bitcoin is now easy but buying and selling Bitcoin is becoming Hard as their are so many scam and cheating ways are moving in exchanges