Help seasoning cast iron skillet

Thank you for any help or advice. I have a cast iron skillet (no idea how old) - Lodge, and it says "CS2" on the bottom if that helps.

It was rusty, so I scrubbed it clean of the rust until it was grey-colored. Then seasoned it four times (light coating of Canola oil, upside-down in a 500-degree oven for a little over an hour, then cooled in the oven).

After all that it has a nice black sheen. But...it's still pretty rough/bumpy to the touch, and it's visible (see photo, sorry about the lighting).

My first use after all this it was pretty far from non-stick and it was really hard to scrape food off it (the first outing was a frittata).

Does anyone know if this is normal? or how I get to the smooth black sheen I see in photos of new or restored cast iron pans?

Thank you very much!!