Beautiful job!!!!! I would grind off as much of the glue as I could. And then I would reassess. You might be ok. Or, if you want to try it, a concrete stain? I would consult with people who do concrete work who might have equipment to gently (?) scour the surface to get the glue off and then seal the concrete for you. But start with the Professionals, FIRST. Good luck. Your home is gorgeous. And bravo in trying to keep true to its aesthetic!

I'm betting that once the glue is ground down after removing the carpet, a concrete contractor could apply a thin coat of concrete to make it as smooth as the steps leading up to the front porch. I agree painting the steps is a maintenance nightmare so I wouldn't go in that direction. And adding another material like slate or flagstone seems not a good idea either, given the ledgestone you already have on the walls.

Give a couple of concrete guys a call and ask their advice.

Another option would be to install outdoor rated thin porcelain tile.

I’m giggling at the carpet. What were they thinking???😆. I second the recommendation for refinishing the entry. I would try to match the sidewalk and put a large, pretty rug outside the door to complement the colors of the house.