Lets say you could go back to the summer 2018. You have the choice to spend the money used for Ronaldo on at least 2 great additions to the squad instead of him. What do you choose?
I know it's not easy to answer it like that, but lets try to play with the knowledge of hindsight.
We don't have to choose. We spent 100m on CR that summer, then bought out Costa from you guys for 40m, bought Cancelo for 40m, bought Bonucci back for 35m, Perin for 15m, signed Emre Can for free (16m sign on fee) and spent another 12.5m on Favilli and Magnani who never played a game for us.
So without Ronaldo we spent 150m. More than enough for two great players.
Then next summer we bought De Ligt for 85m, Danilo, Kulusevski (in January), Romero and Pellegrini for 50m combined (never played a game for us), Demiral for 18m and again Ramsey and Rabiot on huge wages for 'free'. 220m in total without Ramsey and Rabiot fees, not bothered to look that up.
Then spent another 130m last summer.
So, without Ronaldo, since his arrival, we have spent 500m (FIVE HUNDRED MILLION), half a BILLION on new players. Some of those deals were fake exchanges like Danilo-Cancelo and Pjanić-Arthur but even with that it is a HUGE amount of money.
Ronaldo did not stop us from spending or building a better team to complement him. Our management did.