Opera used to be a fantastic web browser, with a custom high-performance Presto rendering engine and features like tabbed windows that didn't show up in competing browsers until years later. However, the modern Opera browser is a shadow of its former self, reliant on chasing trends and meme advertising to
Firefox’s total global market share is 3.3%. They’re practically losing their influence over the web with numbers that small. So while I’m generally in favor of letting people access the web however they’d like, I’m not naive to the idea of advocating for the little guy.
More importantly, using Firefox (or any of its forks) would mean less people are dependent on Google’s Chromium. With less people depending on Google’s Chromium, the less Google can swing its weight around, imposing its dictum on unsuspecting users.