The article makes a number of questionable assertions such as "Non-personalized ads cannot economically sustain Meta’s services". I do not know whether that is true or not. Apple has a history of malicious so. I think there are multiple reasons the US dominates tech, and I do not believe "the EU’s rules all but ensure there are no comparably successful European companies". There are many successful European tech companies, as the article mentions later on (it links to a list of the largest that is clearly out of date - for example that omits ARM).
I also disagree with its analysis of why. If you look at their list of large tech companies, and there are a lot of Chinese ones which largely exist because China was protectionist and favoured domestic over US companies. I would argue, if anything, the EU (and other European companies) have not regulated American companies enough, to produce their own competitors. In particular they rarely block takeovers by established players of potential future competitors.
I agree the EU's approach to regulation is often badly flawed, but the DMA seems to be a reasonable approach - as other comments have said it only targets businesses with a lot of market power.