There are some positions that is very difficult to get someone who can actually do better there for a team. Rodrygo's position is that type of position. It is rare to see someone like Rodrygo to fit in a team like Real Madrid and do better.
I doubt Real Madrid will accept any offer right now for Rodrygo. The club is very comfortable financially if not i would say that could be a reason for them to sell the player.
On personal reasons, there are more reason why Rodrygo will not choose to leave as well. One good reason is the fact that he can win more title easily in the LaLiga with his fellow team mater.
Rodrygo is performing very well in his position and if Real Madrid ever play any other player in his position, the performance is not good from that position. As you said Real Madrid is a very rich club financially so it is very unlikely that Real Madrid will accept another club's offer to sell Rodrygo again. Rodrygo is at Real Madrid and Real Madrid are getting good performances from him as well as Real Madrid but the star is doing well on his own. Now, if this star player is sold to another club, then Real Madrid may face a lot of problems in this particular position, while Rodrygo may not do well in the position he plays in other clubs. The best decision would be not to sell this player to another club but to put him to better use at Real Madrid.