Ignoring an issue is not the same as an issue being nonexistent
tumblr has a thriving radfem/TERF/transphobia scene like twitter
tumblr posts spread conspiracies and disinformation like tiktoks
tumblr users share fake news and misinformation like facebook users
Assuming these issues don't exist on tumblr because you haven't (to your knowledge) seen them does not mean they don't exist. In fact it makes you more vulnerable to falling victim to believing misinformation and being radicalised because you've internalised a sense of security and superiority.
Tumblr is not an inherently better or smarter platform than any other. You can and inevitably will be exposed to these things even here.
Drop the superiority complex and learn about how to actually protect yourself from falling for misinformation, because being on tumblr does not automatically protect you.