Does using an older iOS make my iPhone vulnerable to being compromised?

Up until a few weeks ago, I was still using a later version of iOS 14. Does that mean that my iPhone was capable of being remotely compromised? Do governments (especially u.s.) have remote access to our iPhone cameras? I get very paranoid about these things and reading online news about Pegasus and similar products makes me seriously scared. I don’t know if this is the right place to post such a question, but quite frankly I don’t know where else to ask to get a straight answer.

[Re-Titled by Moderator]