It seems like I asked for this feature in Brave Browser a couple years ago and received no reply from them (from whomever). Both Brave and Opera promote themselves as and are low-bandwidth browsers, but neither of them (are able to?) stop the auto-loading of video. Surely adding this feature would reduce data-consumption greatly for the type of browsing many or most people do.
I'm sorry if I'm here without having done my due diligence in finding a way to stop auto-loading, but I've looked for it ad nauseam not long ago with no success.
Stopping auto-play is great, but it saves little bandwidth in comparison to the data being consumed unnecessarily by the continued loading of any given video on any website I might land on.
I don't know if or when Opera ever sees these comments, but I hope it will add this feature and would not be at all displeased to see it gain market share from Brave for doing so 
(nothing against Brave 
)