Installed new water heater yesterday, today there is water in the catch pan
Possibly the tank leaks.

But it is far more likely that one of the through-hole connections is loose.  Check those before blaming the manufacturer:


Inlet (cold supply)
Outlet (hot output)
cleanout drain
heating unit


Well, I suppose if the heating unit is causing the leak, blame the manufacturer.

The top connections are easily checked by stuffing a paper towel or rag and see if they sop up anything.