Why do we assume Mbappe will join Real Madrid? Despite his desire to play there, would La Liga be as exciting without Messi and Ronaldo every week? He has proved that he is determined to win the Champions League, which PSG, even with Neymar, Messi, and himself, couldnt achieve. Still, thinking about him playing in the EPL, where the competition is stiff and the weather is so different from Parisian nights, makes me laugh.
Regardless of anyone's assumptions about this, if Mbappe wants to win titles in the domestic league and Champions League next season. So Real Madrid is the more appropriate team for him in that regard, even though other teams are also more appropriate, such as several teams in the EPL. However, considering the competition and the very different weather as you said, the consideration might be quite correct if Mbappe wants to choose Real Madrid as the team that will make his career even more brilliant than it is now.
Real Madrid still remains the best choice place for him to go because there, there's a position which he can fill already and that will help him shine better and that has been where he most likely choose over others, going to English team will not avail him all the opportunity to really utilize his potential to the fullest as there will be too competitive and their style of play differs so much which take him so much time to adapt.
He will be better of in la Liga especially in Madrid where he will have less of troubles to deal with ranging from the coach to the management of the team and the atmosphere as a whole, moreover the competition in la Liga is fair enough for him to get familiar with quickly than he would have done with English teams, and he may most likely get a higher offer from Madrid than other English teams.
Real Madrid is a better place for him to explore and achieve his dream of winning a local league and the champion's league, Madrid has that potential much more, so Madrid remains the best option and I think he will most likely choose Madrid over other teams as I still think Madrid has the potential to gat him to the peak of his career quickly than others would have.
That's up for debate I guess because I think Mbappe would fit very well into a top Premier League team as well. That would be the highest competition he can look for in Europe. But I agree that Real Madrid would also be a great destination for him, but it wouldn't be as competitive in the domestic league. Though it would make an amazing attack line for Real Madrid if you combine Mbappe with Vinicius Junior. But when Liverpool one day builds a new team as well, it would be an exciting idea as well, wouldn't it? He could be mainly responsible for a new era in a club.