Damp soil and standing water are two different loads on the wall
Soil against a foundation wall is almost always damp. Ground moisture moves through the pores of concrete slowly, by wicking rather than by pressure, and it turns up on the inside face as a cool patch, a musty smell, or white powder blooming out of the surface, which is efflorescence. That is what dampproofing is aimed at, and a coating handles it.
Standing water is a different load entirely. When the ground around a wall cannot drain, water collects and pushes. It finds a tie hole, a honeycombed patch, a hairline crack, a cold joint left where one lift stiffened before the next one landed on it, or the seam where the wall sits on the footing, and it comes through under pressure. A coating painted on the face does not stop that, because it is thin, it follows every imperfection in the surface underneath it, and it cannot bridge a crack that opens up two winters later. A membrane can.
There is one short window when the outside of the wall is reachable
This is the whole reason the sequence matters more than the product choice. The outside face of a foundation wall is available from the moment the forms come off until the moment dirt goes back against it, and that is the only free shot at it anybody gets. After backfill, reaching that face again means an excavator and a bill.
Inside that window, in order: the wall cures enough to strip, the forms come off, snapped tie ends come off and their holes get filled, ridges at the form joints get knocked back, the coating or the membrane goes on, the drain and the stone go in at the footing, and then the dirt. Skip one and the only route back to it is to dig the wall out. The same order applies whether it is a full basement wall or a shorter stem wall under a crawl space.
Nothing sticks to a wall that was not made ready
This is the step that gets rushed, and it decides whether the rest of it works. Both a coating and a membrane bond to the wall face, so either one is only as good as the surface it landed on. Tie holes left unfilled are direct paths through the wall no matter what is painted over them. Honeycombing, the rough gravelly voids left where concrete did not close around the steel, has to be cut back and packed rather than painted over.
Fins and drips at the form joints matter more under a membrane than under a coating, because a sheet cannot lie flat over a ridge, and a void behind a membrane is a channel for water to travel in. The wall also has to be cured and dry enough for whatever product is going on it, and every product has its own rules about that. Our part in it is handing over a wall that is stripped, patched and straight, which is what makes the next step possible at all.
The drain does at least as much of the work as the coating
Neither product substitutes for getting water away from the wall in the first place. The drain at the footing, free draining stone against the wall instead of clay, the filter fabric that keeps that stone from silting up, and grade at the top that runs water away from the building are doing the heavy lifting. The coating or the membrane handles what is left over.
Run the logic backward and it explains the whole decision. A wall with a working drain and clean stone behind it rarely has standing water pressing on it, which is why dampproofing is enough on most dry, well drained lots. A wall packed in clay with no drain will eventually find the weak spot in any membrane you put on it, and it will have plenty of seasons to look.
Whose scope this is on a job we pour
On most of the walls we pour, the coating and the drain are not ours, and we say so up front rather than quoting work we are not doing. The builder or the site contractor normally carries that scope. Ours is the footing and the wall: the layout, the forms, the steel your prints call for, the sleeves and blockouts, the pour itself, consolidating it, then stripping and patching.
What we do carry is the coordination, because the window is short and everybody has to fit inside it. When we strip a wall we want to know who is coating it, what day they are coming, and what is going against the wall before backfill. Tell us on the phone who has that scope and we will work our schedule around theirs. If it turns out nobody has it, that is far better to discover while the wall is standing clean than after the backfill is already booked.