It has always been so for long. Real Madrid or Barcelona will definitely win the league next season, but we can't tell for sure which of them is the favorite. Barcelona only added one or two players to their squad and the team bond is already there. Unlike, Madrid that has a new coach and needs to understand every player potential so that, he can use them at the appropriate time for the right wings and positions.
We can’t say both of them will definitely win the league next season although they both have a combined almost 90% chance of winning it but Atletico Madrid is always there to give them an headache if both of them gets a bad season Atletico have won like 2 Laliga in the last 10 years if I can guess correctly so we cannot utterly just rule them out even though with this current squad I don’t think they can actually win it but they have to be in the equation. For now Barcelona as the reigning champions have the most odds to actually win the title because Real Madrid are not looking too ready already for this season even with the little additions they have made.
As for Chelsea interest in Rodrygo, it is still a rumour, that guy is good I even wish Chelsea can go for him but as it stands I Chelsea have one already and I know you know who he's is, so going for him may not be their priority.
Although Chelsea have the money to sign anyone right now and with the project presented by Chelsea many players will definitely want to sign for them but I think they will be having problems with signing Rodrigo due to his wages. Chelsea do not pay more than €150k of recent and Rodrigo will be actually looking to recieve more than that