At what pressure? The one you need. a 100lb woman doesn't need much to not have the "floppy tire" effect on the road. OTOH a 300lb big boi will need near max to avoid that issue. Also, on the dirt it's less of an issue since if you go low enough on any tires you get floppyness, but with tubes like BITD you worry about pinch flats or rim impacts which are common on rock gardens under 20psi on old xc tires.
Max pressure can work well on the road if you need it, and don't mind the "firm" ride feel. a 1.5 or 1.9 at max pressure is still more comfy then a 23 at whatever pressure you run it at, and near max you have enough support for the tire to not squirm on a curvy, fast road descent.

I found on a 1.5in tire I needed 60+psi(max 85) to not get tire squirm as a 210lb rider. On the front. On other tires with thicker carcasses(heavier, slower rolling) or wider size you can run less pressure.