Take a look at the Kiwi Broswer [1] it's a fork of Chrome for android, lets you add extensions and has a built in dark mode and ad blocker. I love Firefox for my desktop but found it extremely slow on android so Ive been using this for about a month and have been really happy.

[1] https://play.google.com/store/apps/details?id=com.kiwibrowse...