Both are effective.

Communicative protests give people hope, get them organized with others, and shift less politically motivated people into taking political action.

Concrete actions, including strikes and civil disobedience, are often initially supported and emboldened by communicative ones.

The problem begins when people expect a concrete action from a communicative protest. (See: Beautiful Trouble)

This is also precisely the reason that at my local hyper liberal, 50501-organized protest, on top of everything I mentioned in my prior comment, there were also people informing others about not just how to engage in boycotts of various companies that provided the biggest material support to this administration, but also getting people to commit to a general strike, something most people there didn't even know was a possibility beforehand.

Communicative actions help to both support existing concrete actions, and also create the hope and motivation for many to start taking those actions. In an ideal world, everyone would simply instantaneously jump to doing concrete actions, but that's unfortunately not a reasonable expectation to have.

Those often come after peaceful protests.

Peaceful protests legitimize non peaceful protests which follow