Any player would be very honored to receive an offer from Real Madrid. Money is not the main factor for players to go to Real Madrid, but because it is easy to lift trophies makes it very difficult for players to refuse offers from Madrid.
As one of the big and most successful clubs in Europe, it is very easy for Real Madrid to get targeted players, not all players can be successful when they join Real Madrid because the competition in the main squad is very tight. One example experienced by Hazard, before moving to Real Madrid Hazard was an important player in the Chelsea squad, now he is only a bench warmer due to not being able to show his best performance like when he was still at Chelsea.
I don't think Hazard situation at Madrid was due to performance but rather fitness issue. Hazard had an injury problem during his first season there and in the second he while getting into the team he suffered a recuperation of same injury. Before he could get back Ancelotti became the manager and already had his team. So It was hard for hazard to get into team. But if you watch his games in Belgium you will see he still has that class
Sincerely players are privilege to play for Madrid so it's hard to turn them down. Man United should just hurriedly extend Diogo Dalot's contract because Real Madrid's interest in him can be tempting to him