I disagree in principle, but let's say the people decide to do so. Not only in US (under section 230) those are not media companies, but in EU too, social networks like Facebook/Instagram/etc. are treated legally as "public squares" and not media companies like BBC/etc. When you defame somebody on Instagram, you're the one being held legally responsible, not Meta. Why would social networks be responsible for DSA violations made by the users? This is beyond the fact that implementing an "instant-takedowns" censorship mechanism is draconian. DSA's Articles 16-17 do not require the person (who can also be anonymous, which is ironic) who is reporting the content to provide >legally sufficient< evidence for the takedown. Which goes directly against what I would consider "normal" in a society where you're innocent until proven guilty. The "trusted flaggers" (article 22) do need to submit more evidence, but this just becomes a problem of "partisanship" and bias. This basically means you can report someone for illegal activity, provide unnecessary evidence(in the legal sense), and the content is taken down, with the "battle" starting afterwards.

YouTube's system of DMCA takedown(the copyright issue being way more serious legally than what DSA is supposed to protect against) is not perfect and cannot be perfect (proven by the fact that content is unjustly taken down all the time). DSA is just the same, except more vague, more complicated and (imo) ultimately worse.

DSA has an appeal mechanism, with an option for out-of-court settlements, which means you can employ independent fact-checkers (certified by Digital Services Coordinators (DSCs)); the list of certified bodies is, of course, maintained by the European Commission. The problem is that these DSCs are appointed by each country's gov., which means there's potential room for conflict of interests not only at a national level(I find hard to believe appointed DSCs are completely impartial to the gov. that appointed them) but also at an EU-wide level(certified fact-checking bodies who are supposedly not influenced by EC when judging cases pertaining to EU in international cases).