1) 2G does not provide much in the way of usable Internet these days 2) Many countries are working to actively decommission their 2G networks - which is a good thing because the sooner they do this the bands can be re-used for LTE
2G is fine for what this phone can display. Opera renders and reformats data on their server farm, so it's not loading megabytes of Javascript and high resolution images over 2G.
I certainly hope that 2G doesn't get phased out for a long time. It is a cheap network that is perfect for IoT devices.