Look, I’m a Linux user, and I prefer to use Free apps. However, the truth must be told: Firefox is not as optimized as Chrome. On older devices, Chrome is twice as fast in youtube playback, and it uses way less RAM overall. Chrome is the better browser in terms of architecture, at least for older PCs (and I have a whole bunch of them). On my main PC, running Debian-Testing, which is a newer PC, I do use Firefox, because it can handle stuff ok with enough CPU power. But for all my older PCs (anywhere from 5 to 15 years old), I have to use Chrome.
Now, if you find me a de-googled, Free, WELL-MAINTANED Chromium browser, I rather use that than Chrome. No, Brave, etc don’t cut it. I want a community-driven, well maintained Chromium browser. Currently, all de-googled versions are not well maintained, or not available as native packages on Debian.
EDIT: So, downvoted, huh? By fellow open source users who don’t want to hear the truth?
You can install LineageOS or e/OS on it (instead of Graphene, if that’s too controversial), and then the 4a is a good phone to use.