For instance trying to force a London when black goes for an early c5 Benoni type setup will leave you worse. Also, if you know your opponent is a Chigorin player, the Jobava variant is just better than the London against a knight on c6 and a bishop on f5. White can get into trouble against a Chigorin playing the standard London. Finally, playing Nc3 (Jobava) instead of c3 is just better against a King’s Indian.
So it’s fine, but it’s better to be a little flexible depending on what black plays.
Hmmm ... Magnus Carlsen is now the best chess player in the world. He is a true legend