You don’t have to stop using Reddit entirely to stick it to them.
Using Reddit a lot less? You are contributing to the overall drop in numbers
Using Reddit to protest? You are reminding others of the reasons which may draw others away and drop traffic over time
Using Reddit to let others know of the viable alternatives? Again you may draw even more people away if they find alternatives that they enjoy dropping traffic further
Not using Reddit for anything other than protest? You reduce the value of Reddit by not actually contributing any useful community content that draws people again damaging numbers.