I suppose that could be one approach, but i believe most people use sandpaper or a hobby knife (x-acto knife). Commonly followed by other post-processing (e.g. priming, painting)
It's mainly a visual thing on my pieces, one can hardly feel it when your run your finger over it. I would like to get it a bit smoother, but haven't been able to get it smoother with slicer settings yet.
Hey man, your first layer isn't getting enough squish by the looks of it. It likes a decent amount of push into the bed compared to some other materials. PETG doesn't like as mush mash down as PLA. So if your printing PLA, try increasing your squish. You can do this via your z offset.
But do you really need your bed at 70? Mine runs and sticks just great at 60. 70 seems a bit warm for pla, as it keeps it just a bit too close to the glass transition temp for my liking. But if 70 has worked for you, then stay there.
But as another suggested, maybe raise your first layer temp by 5 or 10 and see if that helps. It might be that it needs a bit higher temp to flow better.