Earthquakes aren't uncommon, but what's happening in Grindavik is more than a earthquake. They were having hundreds of quakes an hour, a fissure opened and magma might come up soon. All in a little town and near a geothermal power plant which also fuels the Blue Lagoon. This also isn't super far from the main airport and the road that leads to it.

During Covid a new volcano erupted quite near Grindavik, that was very tourist friendly: close to Reykjavik, not too large or dangerous, nothing it could damage nearby, a few km hiking from a road. Many web cams were setup and lots of beautiful drone footage was uploaded to YouTube as well. It erupted again 2021 and 2022. So it's a well known volcano now to the Internet public.

Now it seems there will be an eruption on the same fissure again, but a) there are many more earthquakes than before, b) the detected movement of magma is far larger, and c) it could erupt anywhere on a 15km fissure line, but right now it seems to do so right in the middle of the nearby town. So it looks like this time it will be a disaster.

There is also a geothermal power plant that heats the whole peninsula nearby, as well as tourist attraction the Blue Lagoon, that are both at risk.

You aren't wrong, but the topic of interest here is the volcanic eruption. They are also relatively common compared to elsewhere in the world, but most are small and not in populated areas. See: https://www.visiticeland.com/eruption/

They are and they tend to be small because of the type of plate boundary they’re associated with. But when they’re coming in large swarms near a volcano which is the case here, it’s a pretty strong signal of an impending eruption.

yes, and earthquakes are also super common precursors to volcanic eruptions