Is that an Australian snow gum? I don’t know doo dah about Australian trees, but that sheds bark like a madrone. Pretty cool!

Best: grind, apply epoxy moisture barrier at 14 mils, apply primer, then self leveler

Ok but lazier and will probably work if you don’t have moisture issues, or if there’s a vapor barrier under the basement slab: apply primer and then SL

Cut all the corners but will probably work if you don’t have moisture issues or landscape drainage issues: apply SL and call it good

If you intend to finish the basement or make it a living space you should absolutely do the first route.