For Ronaldo returning back to Manchester United to play for the second time shows he loves the club very much. Manchester United are not good with their players both on the pitch and outside, each time their player leaves the club being signed out or on loan they become the headline of the new club while returning back from loan things goes for the worse. It's a problem with Manchester United, not just financially but things might be wrong somewhere that isn't said publicly. CR7 is not who they needed to revive the club, what they need is new experienced signings and a good lineup.
You're right about that. Personally, I've seen that many players who leave MU have no desire to return However CR7 tried to change the story and was treated practically like garbage, where they showed him no empathy for the serious moments his family was going through, This speaks very poorly of the club on a humanitarian level.
When Cristiano Ronaldo first played for Manchester United, Manchester United was in good shape and they were a very strong team in the Premier League, but when Cristiano Ronaldo came to Manchester United for the second time, Manchester United was not in good shape. The club's condition was already bad, then the manager did not give much importance to Ronaldo and insulted him in many matches, put him on the bench and put another player in his place.
Because of this behavior towards Ronaldo, many Ronaldo fans who supported Manchester United stopped supporting this team. Cristiano Ronaldo was insulted, but Cristiano Ronaldo signed a contract with a club in the Saudi League instead of going to any other club in Europe.
Ronaldo left, then players came to Manchester United, and players left again, but Manchester United's position is still at the same level as before.