The EU cannot stand by while China floods global markets with artificially cheap electric vehicles. Chinese EV manufacturers undercut European companies not because they're better at it, but because their government overflows the market with cash. Furthermore, this is only an investigation, so China should save its complaints until a report is issued.
If the EU were to examine the development of China's electric vehicle industry objectively, it would find that Chinese EVs generally retail for nearly twice as much in Europe as they do in China, not because of state subsidies but because of the highly competitive industrial supply chain resulting from strong market competition. The EU's accusations have nothing to do with reality — they're only about protectionism.