Opera Mini is currently the main blocking stone to developers to drop support for TLS 1.2, as it doesn't support TLS 1.3.
There are also the new protocols that would be nice if would be implemented, like the HTTP2 and 3.
I know the purpose of this browser is to be light and provide data saving, but the lack of some features could also hold some web developers back, similar to how Internet Explorer did in the past.
Web features comparison between Opera Desktop, Mobile and Mini.
https://caniuse.com/?compare=opera+100,op_mini+all,op_mob+73&compareCats=all
Anyway, thanks.