I think John Walton and other Genesis scholars make a good case that yom in Genesis 1 does indeed refer to a normal day, not an era. But that doesn’t mean the whole passage should be taken as objective historical narrative, that is a separate interpretive issue.
We had a big long discussion about this not too long ago and some people had some very detailed responses. You would have to skip over all the irrelevant bunny trails, but there is some good stuff here. The Meaning of the Word "Day" in Genesis 1