I see the benefits but cannot trust that there won't be a breach and all that info will be sold leading to identity theft. Centralized systems have just been shown to fail over the past ten years.
Can't speak for all countries, but some countries like Estonia, identity is stored via asymmetric certs that can't be downloaded off your card. The only thing centralized afaik, is the authority cert. If that gets compromised, all signatures require a trusted timestamp, so you can easily invalidate signatures made with false or compromised certs.
In Belgium we have a similar system, also fully open source. It's pretty cool that different countries are going to be using the same system soon.
The only thing that worries me is that the EU has this habit of creating open source libraries and releasing it under a permissive license, which is then incorporated in proprietary apps. This also happened with the corona contact tracing. Germany made their app open source, Belgium didn't, but I could just use the German app instead.
Another example is the Belgian eID stuff. Anything government related uses the open source tech, but ISPs and banks made their own proprietary app that does the same thing, and then everyone started using this crap. Now, the government started paying a third party to make yet another proprietary app that does the same thing, but no one cares about it or uses it.