Every coach has different tactics and different player selections, and it's undeniable that Rodrygo is a quality player, but Xabi Alonso has his own preferences.
Right now, there's no other option for Rodrygo than to move to another team. Even if he stays at Real Madrid, he won't be able to secure a starting spot, which would hinder his career development. He's still very young, and there are still many possibilities for his career, so I have little hope that Rodrygo will move to another team.
Rodrygo could still fit into Xabi's system, if Xabi wanted to, it is not really that shocking. Only trouble is, there are way too many great attacking players, so they need to figure out a way to spread to right a bit. Vini, Mbappe, Jude, all great attacking players without a doubt, Valverde comes to help attacking from behind quite often, so they need one more that would be on the right normally.
But instead, Xabi uses Arda there usually, or Garcia, if you just remove those and put Rodrygo in, then it still works, tactic still works. Just look at the club world cup games, see Garcia and Arda, and remove them in your mind and put Rodrygo in. Could you say it would have been worse? Sure it is not like right attacking winger position, it's more like right midfield, but it still works, he would still be better.