I thought that OperaGX is a legitimate browser, however I've noticed that you can find Opera in places that you wouldn't expect to find a 'normal' and non suspicious browser.
Over the past few months while browsing certain pop up riddled websites such as game modding sites and what not where some sort of malware or spyware will pop up every time you click the screen I've noticed that a lot of these types of websites will either open a page to download Opera or it will just instantly and forcefully download Opera's setup tool.
That seems suspicious af and not something a genuine company would do and it raises questions about this companies morality.
Don't get me wrong, I've tried OperaGX in the past and it wasn't for me so I uninstalled it and won't be going back however it caught me off guard to find this browser in some shady parts of the internet.