The 3 RS-25 (1860 kN each)[1] used for the Space Shuttles had 300,000 Gallons of water output per 41 seconds [2] when it launched. On landing, the Falcon Super Heavy used 5 or so [3] of the Raptor Engines (2750 kN each [4]). I'm making a few assumptions based on Napkin Math, but the parent comment seems about right since the engineering required (and the payload weight lost due to the weight/space requirements of landing feet for the FSH), would be too high to withstand the vibration reflection of landing on solid landing pad.
[1]https://en.wikipedia.org/wiki/RS-25
[2]https://en.wikipedia.org/wiki/Sound_suppression_system#NASA [3]https://www.youtube.com/watch?v=pIKI7y3DTXk&t=6850s
[4]https://www.spacex.com/vehicles/starship/