However, I’m not French, it’s not the 90s, they’ve been married for 20 years now. By all accounts it’s been fulfilling and satisfying marriage…

I don’t think the first two points matter, but yes - if he’s happily married then there really isn’t anything to be done. How it started was wrong, and I do wonder what Macrons life would have been like had he not been manipulated by someone 24 years older than him. Not that it matters, what’s done is done.