According to WorldBank data China does spend approx 1.9 % of GDP which is a bit more than USD 250 Billion.
According to Wiki the EU-27 did spend Euro 225 Billion (approx USD 250 Billion at 1.10 currency rate) and this is in 2018 approx 1.4% of GDP.
https://en.wikipedia.org/wiki/Common_Security_and_Defence_Policy#:~:text=Expenditure and personnel,-Further information: List&text=The combined military expenditure of,and joint procurement of equipment.
If it is a numbers game....
Is 2.0% the norm... or is absolute amount equivalency with China the norm ?
The EU can easily spend some more money on military.
It means shifting some money from amenities to military insurance
That military insurance will cause some second order effects mostly better stability-continuity, beneficial to mitigating risks on the EU way of life.
But on what to spend that money, on what to spend those resources you tie up ?
And which regions, countries will enjoy the economy of the military industry and salaries and which regions, countries will just pay up ?
And will for example salaries paid to countries with lots of unemployed people lead to soldiers defending EU interests in other countries ?
And what military ?
More of the same of the last war like tanks ?
Do we need for the EU those costly air carriers ?
(how much is that alone already for the US military cost as % of GDP ?)
How much of future military is related to cyber war ?..... needing urban dweller nerds.
Then there are the attack submarines, the nukes, etc... what to do there beyond some vanity projects.
etc
If the US could re-design its complete military without the inertia of vested interests of politicians and States, of industry and military salaries.... and could swap from A to B without transition issues... how would US military look ?