I used it for a good long while up until, like many are chiming in now, I read the message that they were removing the free version of the extension due to the upset generative AI is causing in the tech world.
I got no condemnation to throw at them for this choice, and I believe them when they shared that they didn't come to this decision lightly, as they likely knew most, if not all, of their users wouldn't be happy and would outright drop them.
I myself am not ready to pay for better spelling, but for those sharing dismay at the asking price, that's fair, but remember, a bill is always due; they've just been able to pay it for us until now.
The silver lining is that there's plenty of other extensions of this nature out there, what's unerving is this one of the only ones on Opera's site, with Grammarly, Quillbot and others available on Google Web Store site.