The difference is that United just won EFL without him, and they will probably finish top 4 without him, and they could potentially even with Europa, or at least go to a good stage without him as well. Whereas Ronaldo will be playing in Suadi league, a league that didn't even had a topic here before Ronaldo moved here, imagine how little it is known for and cared about, Ronaldo himself is bigger than this league all by himself, so it's definitely not a good idea.
I would say that the money he is getting is basically reward for his career, that's a good thing and I support it, but do not consider anything he does here as achievement, definitely not it.
Logically linking the departure of Ronaldo and winning the title by United is rather strange, it's following the haters. As if there was no like a "modest" purchase of the great Casemiro and an emergency rebuild of a team that was very weak at the beginning of the season (with and without Ronaldo). Whether his game is an achievement in the Saudi League can be discussed later - if he sets records again, then why not.
He may have hit the jackpot, but he deserved it. Manchester United was severely underpaying him ($17 million per year). He maybe 39 years old, but Ronaldo still commands support from hundreds of millions of fans around the world. Both Manchester United and the EPL benefitted from his presence in the league, but they refused to adequately compensate him. Al Nassr noticed the opportunity and they made a deal with Ronaldo. The lesson to be learnt here, is not to disrespect your legendary players. Hopefully ManUtd would learn from this lesson.
Yes, Ronaldo fully deserves what he has, I must have misused the word jackpot since there is no question of luck here, this is the result of labor.
As for United, apparently their paths with Ronaldo should have diverged for objective reasons, but it’s a pity that United acted unprofessionally and as a result they greatly damaged their reputation.