As with many poker questions, the answer is that it depends. Basically, if the goal is to maximize your winnings, that a matter of finding the sweet spot where your EV is highest. This involves a combination of considerations including but not limited to what types of game, what stakes, how many tables, and on what site.
There's no single answer, which is why, for example, there are successful pros who specialize in MTTs, SNGs, ring games, various forms of poker, heads-up, etc., etc.