Two distinct reasons for this IMHO.
1. The EU is (almost entirely) formed of established economies (bar a few in the former Soviet bloc), and established economies, by definition, do not grow quickly because they're already big. By contrast, most other trading blocs included a lot of less developed countries, the former TPP containing a number of economies in south east Asia which have experienced phenomenal growth in recent years as they are starting from a lower base, meaning the average growth across the bloc would be higher as a result. Meanwhile many of the real basket-case economies of Europe are currently unable to join the EU (despite many of them wanting to) because of threats from Moscow should they choose to do so.
2. The global financial crisis of 2008 disproportionately impacted the countries in the western hemisphere, especially ones which rely heavily on a services industry such as the UK, France, Germany, the US and the Benelux countries rather than raw materials. As the major financial centres of the EU this had a net negative effect on the performance of the entire bloc when you take into account the average of all the relevant members, whereas a nation such as China or Brazil did well out of it as companies sought safer havens and those where land value and housing were less expensive became more attractive.
