Note that I said second most powerful. And yes, the size of a country's economy is one of the major factors when considering its geopolitical influence (though obviously not the only factor).
If you disagree, which country is #2 if not China?
Russia, that just tried to take over a country with 1/14th of the economy and 1/4th of the population, failed, and is at this very moment having its own territory invaded in turn? Meanwhile, China has roughly double the military spending, 50% more active personnel, more weapons, and almost definitely more morale and discipline. And while China's military might be less tested, Russia's was just tested and it broke.
It was also really funny when their elite mercenary corps turned around and bum-rushed Moscow.
> If you mean geopolitical influence, id say the major European countries
China's Exim Bank finances more than the total export financing of the G7, combined[0]. China's foreign aid program rivals members of the G7 as well.
But it's not fair to compare the G7 or the whole European bloc against a single country. So let's say Germany. Sure, they're popular with the US and their continental brethren, but their influence on countries outside that sphere, particularly developing countries, does not match China's.
For instance, they don't have anything like China's $100-billion Belt and Road initiative. China has also invested all over the world in everything from infrastructure to mining projects, even in G7 countries. And in spite of the West's pullback, they're still the "world's factory", while Germany has had difficulty keeping its (recently declining) manufacturing industries competitive against China's[1]. Germany, like many countries in the world, also relies on China as its largest trading partner.
So given the data I've seen, I can't say any one European country, or even a handful, matches up to China. This would make sense given China's much larger population, staggering industrial capacity, aggressive worldwide investment strategies, and leadership among dozens of developing countries.
If you disagree, which country is #2 if not China?