Firstly, the USA has Silicon Valley: a vast concentration not just of skills, expertise, labour supply, but also specialised tech finance that can fund things absurdly up the wazoo with so much money that they can expand madly without having to make a profit. China has been a closed shop that has effectively isolated and protected itself from competition to build up its own industry, where much European stuff has been bought out by foreign firms.
Europe has a pretty good tech industry, it's just not got so much in the way of homegrown massive multinationals.
