That is one form of attack, but that's "the nuclear option" of infrastructure. It's a concern, but many of the concerns around 5G are persistent nation state spying activities. China is far more concerned with data aggregating and mining than it is with nuking the West. China, in general, tends to avoid cataclysmic actions that upend the current order. Especially given that most of the Western world is China's largest trading partners and a fundamental part of their economy.

China's strategic plan is spy and collect, not destroy. Traditional espionage stuff that every country does.