Is there a particular reason? And how do you know so much about 2G in Finland, specifically!?

Portugal will keep it too.

Dumb phones are still being sold that are 2G only.

Not just that, but “landlines” are still being offered that are really a 2G phone restricted to work only in the vicinity of a home that's not (yet?) covered by actual landlines.

It's also used by emergency services.

It's considered a technology of last resort, and the service provider that wins the concession to provide it, with 100% coverage of a given area, probably finds it useful that it can meet the conditions with such tech.

3G has already shut down.

Denmark does the same. 3G has been shutdown, or mostly at least. 2G is kept running, with no plans to shut it down in the future.

Things that uses 2G:

  - Electricity meters
  - Alarm systems
  - Cooling and heating systems
  - Rat traps (?)
  - And an absolute crap-ton of early "IoT" devices.

And it's considered a backup network, with better coverage and range than 4G/5G. It also makes sense as the country is actively starting to remove the old landlines. The first cables are actively been removed from the ground.

Yeah, there was a lot of debates when they started relying on cell networks for alarms systems (mostly for the elderly) as a way to not have to maintain the copper.

A guess...

1G (NMT) and 2G networks have been used in forestry. Very often the machines are far from a mast and need the extra range to communicate.

And in general Finland is a sparsely populated country.