If you want Tumblr to lift the porn ban, you have to call your elected officials and loudly complain about the FOSTA/SESTA acts that are the reason the ban exists.
And you also need to be ready to stand shoulder-to-shoulder with the sex workers who have been fighting the ban for years.
If you want porn back on tumblr but don’t want to stand with sex workers having the right to run their business, then you don’t fucking deserve porn on tumblr.