For people who are interested in this, there is an esp32 component (and works awesome) https://esphome.io/components/sensor/dsmr/

There are also several cheap hardware sold with p1 port connection and home assistant integration.

Is this really Dutch-specific, or is there a chance other modern smart meters in other EU countries might use the same protocols?

It’s nice living in de Netherlands, you can read your energy meter with DSMR indeed (and get all the data including solar delivered back to the network etc). Or you buy this thingy [0], plug it in and boom all data flows into Home Assistant’s very excellent energy dashboard.

[0] https://www.zuidwijk.com/product/slimmelezer-plus/