This account has been inactive for 5 months and just recently had the password changed, returning with a different posting habit. I suspect it to have changed hands, to help that, can you sign a message from an old bitcoin address that was posted by this user, preferably 2+ years old?

About your question, if you have the capital, then Bitcoin is a reliable investment option. Some people will want to try staking since you're talking about passive income, but I do not recommend. If you're lacking in capital, you can market a skill and get payment in bitcoin to build your stash.