Are these bags actually waterproof, or just water-resistant?

Almost all of them are water-resistant rather than fully waterproof. Verified-purchase reviewers note that nylon and PE bags shed splashes and damp grass fine, but submerging a soaked pair of trail runners will eventually wick through seams and zippers. For genuinely wet shoes, reviewers recommend bags marketed specifically as wet/dry pouches, like the pack-all design.