In this case, it is likely that age is one of the factors that are considered. Ronaldo's age is 37 years old, so it is quite difficult for big clubs to consider him even though he can still be competitive but of course this will not last long because it is certain that at his current age there are only a few years left for Ronaldo and the EPL is a match that does have intensity. so that instead of looking for old players, big clubs would prefer to look for young players who have great potential to be awarded contracts.
I think one of the reasons most clubs don't want Ronaldo is as said, due to his age and experience. He is past his peak performance and can only be of much use in leagues with less stress, unlike the English premiership. Also, with the vast experience he has garnered over the years, he might be too heady or superior to the managers or team members. It is also likely that if Ronaldo is in a team, the game is kind of bound to be centered about him. Managers know this, and dont want an influence bigger than theirs. If I were him, either I go to the Spanish league or to the American league because he still has to remain fresh for Portugal in their oncoming world cup campaign.
Actually, in this case for the EPL, he can still do it, but indeed we also know that in the EPL there are a lot of criticisms if the performance is not as expected. Moreover, in this case we know that Ronaldo's salary is still very large for a player of his age so it is indeed difficult for a big team to bring him with such a high salary at his current age.
As for MLS, I am personally not too sure because even though he is currently quite old, he is one of the players who has high ambitions so MLS is not a place that can satisfy Ronaldo.