You’re describing parties that stand for nothing, and are therefore useless. Which is accurate.
In general parties have to lose their focus in order to grow. This is the flaw with a two party system.
Unfortunately we are a long way from establishing viable alternatives, and the leaders of the past have, in general, been no different than those of the present in that they were unwilling to abandon the power and security provided by diluting the message of their own party rather than creating a new one.
Of course, it would help if the major new parties that get attention weren’t generally founded by nutcases.