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
TL;DR company shady
The main 3 points seem to be: China-owned, predatory loan applications, and spreading themselves across too many concept/trend browser spinoffs. Honestly this is kinda old news and won’t stop anyone I know from using the thing. You can’t just say they’re “probably” harvesting your data for “nefarious” reasons and expect people to all jump to Firefox (as nice as that may be).
I’d add a fourth main point: they have a documented history of creating browsers and then abandoning them, leaving any unaware users without security updates indefinitely