But its relative GDP growth has been higher than the US for decades, is higher stil and is probably going to stay higher for years:
https://ourworldindata.org/grapher/real-gdp-growth?country=U...
If you look at absolute numbers (https://ourworldindata.org/grapher/gdp-worldbank-constant-us...), it seems likely that China will surpass the US economy pretty soon (they're a lot more people though, so per-capita is much worse).
Personally I think its most likely that chinese GDP will be larger than US GDP within 2035, but that the median citizen is NOT going to catch up to US standards in the next 50 years.
And their whole society will run into the exact same problems that many western countries are dealing with already (increasing fraction of retirees), so I'd be very careful with extrapolating their currently superior growth rate past 2040 or so.