Bigger is NOT always better
The bigger the better bit is a bit of a fallacy.
Choosing format size is extremely important in delivering the best possible end result. Assuming you have a choice of using 35mm, 120 or 5"x4" (or larger) there are a number of other considerations. Probably the most important is do you want to use a tripod or hand-hold.
Of course you then have to decide on film stock & it's speed.
Subject matter ultimately dictates format & film choices, and landscape can be shot in any format on any film and you can achieve excellent quality results, and sure the larger on a tripod will be far better.
Now what about people, of course great shots have been made with large format, one only has to think of Irvin Penn's work, but here on this forum (and elsewhere) great images are being made on smaller formats, the work of Nicole McGrade could not be made large format nor that of Cheryl Jacobs. Before you ask I've had no contact with either they just happen to have posted images recently.
So choice of frormat is made after taking into account a wide range of factors, which really relate to practibility and expectations.