Real Madrid is a club with known potentials, no any player that comes to Madrid and flop in his performance, at best their signings are perfect, they don't sign many and the worth of their players purchased are not the highest of them in the transfer market but after a while with Madrid those players market value will increase a lot. I think it will be hard to see Madrid fail to be this outstanding, their mode of selection including coaches and players is what is keeping them still on the run and in regards to the club management unlike some Premier League teams whose club owners are part of their failed performance.
In fact, there are also several players who failed when they joined Real Madrid, but there are only a few or more who were successful with Real Madrid. They are quite smart in recruiting players, they don't waste a lot of money buying players who don't make a big contribution. They are good at building their squad and the depth of their squad is evenly distributed so they can rotate freely.
Even in 2016/2017, for example, the majority of the main players were captains of their respective countries, this is something we very rarely see in football. They can do all this because their finances also support them. If their finances didn't support them, they wouldn't be able to do something like this. So that's why finances are a very important factor in football, because with a good financial situation, they can freely do anything as long as they don't break the rules.