Ronaldo is clearly struggling at the moment.
Yes, some of that is his age and declining abilities compared to the amazing player he was in his prime. But I definitely think he'd still be finishing more of these chances, and would be on a much higher goal tally, were it not for missing pre-season (whatever the reasons behind that) and so playing catch up physically on everyone else, and as a consequence struggling, beginning to lose confidence and start to snatch at chances, as a consequence missing even more and losing more confidence in front of goal, etc.
it's a vicious circle when a sports player is struggling for form. You hear them say it all the time. You get into that spiral and it's tough to get out of it as you get more desperate rather than just calmly thinking it'll turn around if you keep doing the right things.
I know many disliked him even when he was in his prime, and so are loving (and have had to wait a long, long time!) to see him now struggling for form. And, because of his actions since the summer, it's easy to say out of hatred 'he's finished' while his form is poor. But he's reinvented himself numerous times as a player - as a raw tricky winger who creates, to a wide striker who scores ludicrous numbers, to an all round #9 who scores even crazier numbers, to an aging #9 who still has very clever movement in and around the box and good finishing ability. That latter player is still there, but the lack of a pre-season has meant a poor start that he's now struggling to get out of.
Hopefully, next season, we'll add a younger #9, whose also more reliable in terms of finishing and fitness than we currently have in the squad. But, this season, I'm sure with a usual pre-season, Ronaldo could well have provided another 15-25 goal return helping finish off the chances he's uncharacteristically missing due to an initial lack of match sharpness, and now rare lack of confidence in his finishing.