In addition to needing time to recruit players, Man Utd also does not have a large budget, that is why until now there have only been a few ordinary recruits that they have made, they do not want to repeat the transfer mistakes in the Ten Hag era, so next season is like the season where everything is at stake in Amorim hands, Amorim must succeed with all the limitations given by management. Replacing existing players is easy but it is not good to replace them without removing them, the difficulty here is because no team has really glanced at Man Utd players.
A team that is not making some adjustments in its squad will fail no matter how good the remaining players are. Just remember when Real Madrid refused to sign anyone except Mbappe and what happened to Manchester City during this season.
Manchester United limiting their choices will force coach to not use his full potential tactics and will be the reason to see himself being sacked for failing while he was limited.
You can't even make such comparison because for the case of real Madrid and Manchester city, they even have options and very good player that even if they didn't sign any new player, it would have been easy for them cope with what's already on ground. Even without mbappe joining real Madrid, vinicius, rodrygo and Jude Bellingham where strong forces that could defeat any team they meet, how well can we say the Manchester United team is?
Next season is going to be really tough for any team that's not investing enough in getting new players into their team. Funds is not really an issue if they want to get a good player, it's just that the club doesn't want to invest into the club and they will eventually pay for it when they start doing bad in the coming session.