WhatsApp introduces ads in its app

Does anyone know what's the state of the art way for cutting crap out of android apps? In the same way adblock cuts crap out of web pages?

I assume one would need a Java disassembler at least. On desktop, something like recaf works and allows changing things in classes without the full recompilation.

Is there something like this for android?

DNS blocking with tools like DNSNet get you halfway there without tampering with the apps. It installs itself like a VPN and filters dns requests to ad domains using lists from the same sources as the adblockers.

I say halfway because some apps have a fallback, built-in, ad when it can't reach the server, other serve the ads from their own servers so no way to block them. Most only leave a blank space.