Preparation takes the time
The polish is the short part.
They come from washing, not from driving. Usually from an automatic wash or a dirty sponge.
The visible result of a detail comes almost entirely from what happens before any polish is applied. Grit left on paint during the wash gets dragged across it; bonded contamination left in place gets polished over. Both show up weeks later in sunlight.
Correction has a hard limit and it is physical. There is only so much clear coat, and removing it is permanent. A detailer who checks thickness and tells you a scratch is too deep is protecting the car; one who promises everything will come out is planning to burn through an edge.
Coatings make that honesty matter more, not less. A coating seals in whatever is beneath it for years, so applying one over swirls locks them in. Fixing that later means removing the coating and starting again.
The polish is the short part.
You see the real result before committing.
Repairs go to licensed shops.
Send photos. Free, with an honest answer about what will come out.