It is?
A player of his level and at this stage of his career shouldn't be wasting his time in the French league.
Yes. Always a candidate for the CL and have a stacked squad, and financial backing to attract any talent.
How are you a fan of a supposedly competitive sport and want to see the best talents always end up at the same clubs rather than, you know, compete?
Staying at PSG and trying to bag them a CL > joining a club that has like 13 of those. I don't support neither PSG or Real, so why would I want to see Mbappe join and strengthen Real - that already has that many CL titles - instead of competing against them and having one more legit candidate in the competition?
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at this stage of his career" - the guy is 23
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b-b-but French ligue" - be honest, outside of Real, Barca and Atletico - maybe Sevilla too - nobody really cares about La Liga like that. Slalom runs against Osasuna are hardly more prestigious than slalom runs Nantes.