I was using brave before and decided to switch to firefox but I did some research and turns out firefox collects way more by default than brave and I am switching back, what do you think?
Untill we get a gecko webview , you are using chromium based , whatever browser you are using. So yea the options are or use chromium or chromium plus Firefox.
I don't know how it stacks up but there's also DuckDuckGo's browser - it has the added benefit of 'App Tracking Protection' which stops other apps from collecting data in the background by using a local VPN. Crazy how much it blocks - even for apps that haven't been launched at all recently.
Firefox has specific issues that chromium based browsers don't. A big one is site isolation or keeping one website from accessing data from another. Those problems are worse on Android than desktop. I do use Firefox with uBlock on desktop but Brave on my phone.
One option is to use the beta version of firefox. It's been reliable enough for me and gives you access to about:config where you can turn off all the telemetry and generally make things a little more secure.