I guess... only visit sites that have a clear source of income? That is, sites where you have to pay for the, um, content. At least such sites might have less of a financial motivation to infect your phone... I guess.
Of course, paying for something on the internet usually means divulging some kind of personal information, such as credit cards. Perhaps you could use a trusted VPN, aliasing email address service, and anonymous (if that really exists) payment methods? So there's that to consider.
And also, I'd use only a fully patched phone with GrapheneOS for this purpose (or must purposes, anyway), and the most secure browser known to humankind me: Vanadium. Ignoring the monetary cost for a moment, ideally you should run GrapheneOS on a Pixel 8 with memory tagging extension enabled. That would also allow you to connect the phone to a large monitor for, let's say, em, increased enjoyment?
Of course, paying for this kind of... content, might involve you making some kind of moral judgments on where you ought to put your money. I would personally read up on various moral and philosophical theories. But that might just be me being, em, a nerd.