Commenting because of this request.
I was a Christian from around age 11-12 until I gave it up. I was never a YEC. I don’t think YEC was a big thing at that time. And, growing up in Australia, there were good reasons to see the earth as old.
Genesis 1 did give me problems, though not because of the age question. There was the problem of light before there was a sun. And there was the problem of sun, moon, stars as light fixtures in a ceiling above the earth. These seemed obviously wrong.
But then it occurred to me. If God was inspiring scripture, then he surely was not dictating words. Surely, it was a matter of giving ideas that people would then write in their own words. So we should expect what was written to reflect the culture for which it was written. While Genesis 1 had problems, it was actually a pretty reasonable account for the time that it was written.
I never had a problem with A&E, or Noah or the tower of Babel. These were obviously of the genre of fables, and not intended to be taken as actual history. My biggest problem with Genesis, was Abraham being told to slay his son. But that was not a deal breaker, because it worked out in the end.
My biggest problem with the Pentateuch was with Exodus, where God hardened Pharaoh’s heart and then punished him for having a hard heart. This is where I began to wonder whether it was man that created god, instead of god creating man. That’s when my skepticism started, though it took another 10 years before I gave it all up.