Are robot vacuums with mopping functions actually worth it?

It depends on the tier. High-trust testing at Vacuum Wars and owner reports on r/Roborock consistently note that lower-end combos (like the Q7 M5+) treat mopping as a token feature — useful for light dust but not real stains. Premium combos with spinning pads, hot-water washing and mop lifting (like the Qrevo S Pro and S5V) deliver meaningfully better mopping, but cost two to three times as much.