I don't think the premier league is the best in the world at all, and I'm English. It just goes around saying it's the best in the world and enough people believe it that it becomes a self-fulfilling thing. The only thing it's best in the world at is marketing.
All the best players end up at Real Madrid, Barcelona and to an extent Bayern. Even Man Utd and Liverpool have been used as stepping stones in recent years for players to get there.
As for "competitiveness", with the 5000-1 exception of Leicester, and Liverpool last season, the only time Man Utd or Arsenal haven't won it in the last 30 years were when the richest club at the time won it instead (Blackburn with Jack Walker's money, Chelsea with Abramovich's money and Man City with the Abu Dhabi
bankroll).
Put it another way, the Charity/Community Shield (England's "Super Cup") - since 1996, there's only been 3 exceptions to it not being contested by 2 of Man Utd, Man City, Liverpool, Chelsea or Arsenal (Portsmouth in 2008, Wigan in 2013 and Leicester in 2016) - so 45 of the 48 sides who have contested it have been one of those 5. In what universe is that competitive? Yes, anyone can beat anyone on their day. That happens in all leagues. Barcelona and Real Madrid suffer unexpected defeats to struggling teams during their league season. The difference is the media don't go round spouting about how that's what makes La Liga great because it's so unpredictable.
I know I'm mentioning Barcelona and Real Madrid as if they're the only 2 clubs in Spain, but even there, Athletico Madrid and Sevilla have had great domestic and European success recently,, and going further back Valencia, Villareal and prior to their financial troubles, Deportivo and Real Sociedad have all competed for the title there or won or reached the final stages in Europe.
As for quality, pick any random weekend. Watch the Premier League goals round up and the La Liga and Serie A goals round up and get back to me about which league is better