I don't think that Trotsky was wrong to hold to a Leninist party model in his time (indeed, I would have said that his greatest failure was not to follow the Leninist principle of giving organisational form to his differences with Stalin and Bukharin, by splitting the RSDLP sooner).
Trotsky was (largely) right for his time, but in ours we face different problems. The Leninist model of political organisation assumes a differentiation in the working class between more and less class conscious workers, and seeks to organise the more so to fight for the less so. But there is no such polarisation in our time.
More than that, I am not convinced that the question of socialism is on the table (maybe this current crisis will change things, but I don't see much evidence of that yet).