Use whatever software you want! These are your devices and I’m not gonna shame you for how you choose to use them. What’s important is that an open web is maintained so you have that choice.
Except the issue is, if people use Chromium-based browsers, then Google still has all the power and has the monopoly. If people use whatever browser they want, and it happens to be a Chromium-based browser or even Chromium itself, then we end up back in the same position as we’re in now and nothing changes.
That’s why everyone is recommending Firefox.