Open-source still has a long-term advantage. Long-term, either AWS goes out of business, “enshittifies” their “enhanced” version, and/or open-sources it themselves. Meanwhile, the open-source version never goes away or gets worse: at worst it will bitrot, but that’s only if nobody is using it enough to put in the bare minimum of maintenance (then when AWS inevitably degrades, there’s a good chance someone makes an open-source rewrite).