This is wrong. The DMA specifically targets only foreign companies: https://digital-markets-act.ec.europa.eu/gatekeepers_en
It only applies to the 6 "gatekeepers," five of these are American and one in Chinese: Alphabet, Amazon, Apple, ByteDance, Meta, and Microsoft. It is legislation designed to tax these companies through fines, moving goalposts, and arbitrary decisions. Please cite me one case where any European company has been fined under the DMA.
Correlation is not the same as causality. Europe simply does not have (m)any big platforms with a VERY strong market position. Because of capital markets, risk adversity, etc.
And the big tech players we have are looked into just as well by the EU based on the whole of the regulations. Some examples:
So get your facts straight. Or stay in your bubble.