You are right, despite Ronaldo's age he has a performance of 10 years less than he has, that is, his performance is like that of a 26-28 year old, this because of the type of training work he has. As an athlete, his care and everything that has to do with the type of preparation, apart from this Ronaldo represents a key to attract people and investors, nothing else on the stock market when he entered PSG made it rise, also as You say he is not the only player in the team, I am sure that Man United will become much more penetrating every time and they will be a worthy team to rival PSG in an eventual CL final.
Ronaldo can play till his forties and with his ambition, he will not stop if his body allows him to play and score goals. He will want to prolong his career as long as possible and try to break as many records as possible.
Like Ibrahimovic or Federer, Ronaldo will keep up his love with the sport he spend his life for.
A good team like Manchester United in last season of Sir. Alex Ferguson only needs a striker like Van Persie to win Premier League. Ronaldo can play the same role as Van Persie and even can score more goals but Manchester United now are different, weaker. The coach is not Sir. Alex and only Ronaldo is not enough.
They need more things from the coach. They have a good team but don't have a good coach.
It's just that the Manchester United management expects further improvement in the team's results and are in no hurry to part with it. Although, of course, if this improvement does not happen, then organizational conclusions on the change of coach will necessarily follow, because the club has spent well on the transfer company. No wonder the club now ranks second in the list of European football clubs with the most expensive squads according to the CIES Football Observatory with an amount of 1.214 billion euros. Solskjaer, at the age of 48, is a fairly young coach and he has a lot to grow, and Manchester United is a great place to do this, it just takes some time.