Volume
IMHO the EU already produces more than 20% of the world's IC's by VOLUME but not by VALUE. The semiconductors made in Taiwan are mostly high-end, used in GPU's, AI accelerators and top-of-the-line CPU's for PC's and smartphones sometimes costing hundreds of dollars a piece.
The semiconductors made in Europe are mostly made using low to medium complexity semiconductor processes for use by the automotive, consumer products (washing machines, audio) and smartphone sector. These are low-cost but made in large numbers.
So it all depends on your metric. If Europe wants to compete with Taiwan, Korea and the U.S. it will indeed have to invest a LOT more money. A single high-end semiconductor plant can cost up to $100 billion these days.