Some pretty bad luck + choking tendencies + moving away from a tactical based meta to a more gunfighty meta are the main problems.
If Boaster/Crashies weren't liabilities in big games (Crashies in every game) FNC almost certainly win in Toronto and Paris, and then the conversation becomes "wow omg EMEA is the best region they went 2/3 this year!!"
Same conversation in 2024 really, but TH should receive more grace as they were a team of rookies.
If you look holistically and compare average placement etc EMEA is not really much worse than AMER/APAC. however this year EMEA has very obviously stunk it up at internationals. why? because weaker teams (BBL, M8, FUT...) that are better at outshooting the opponents and weaker tactically win the "rock, paper, scissors" game with the rest of EMEA who are better in slower, more tactical games and much weaker at controlling aggression, then go to internationals and play teams from other regions who love that style and play against it every week. Being ran down by BBL is nothing special to PRX, for example.