tumblr still works but not like before, traffic is way lower now and most people using it just for niche stuff like fandom, art, quotes etc, overall platform still got around 130M+ users but engagement and reach dropped a lot so dont expect big traffic , from what i see and others also saying its more like side traffic source now not main one, u can still get some clicks if your content fits tumblr style but for serious lead gen or affiliate its kinda weak, better use it as support with other platforms not rely on it alone.