Is it true that distributaries form in all deltas because the deposited material blocks the river channel...?

...and the river has to split to go around it???Is it true that distributaries form in all deltas because the deposited material blocks the river channel...?
A distributary, or a distributary channel, is a stream that branches off and flows away from a main stream channel. They are a common feature of river deltas. The phenomenon is known as river bifurcation. The opposite of a distributary is a tributary. Distributaries usually occur as a stream nears a lake or the ocean, but they can occur inland as well, such as in an endorheic basin, or when a tributary stream bifurcates as it nears its confluence with a larger stream. In some cases, a minor distributary can ';steal'; so much water from the main channel that it can become the main route.Is it true that distributaries form in all deltas because the deposited material blocks the river channel...?
Damn, I'm calling my cable company. I don't even get the River Channel!