Is fishing from a drift boat better than fishing from shore?

There are a lot of things that factor into this but most of the time yes fishing from a drift boat is better than wading. 

One example is during high water the drift boat offers the ability to cover a lot of water and fish from the best side of the river. 

The drift boat give you the ability to cover a lot of water during the day. You can move from spot to spot with ease. 

Fishing from a drift boat allows you to carry a lot of gear. This allows you to fish with different techniques throughout the day. You might start out fly fishing and change over to float fishing after seeing some fish caught on egg sacks for example. 

When walleye fishing I have proven over and over that pulling plugs from the drift boat is much more effective than casting them from shore. This technique covers much more water allowing more fish to see the lure.