Interestingly, my country turned off 3G before 2G.
I think the reasoning was that the heavy data 3G users had already upgraded to 4G and beyond, and low data 3G users could fall back to 2G, so retiring 3G would have negligible impact - while opening up a lot of bandwidth for 4G and 5G.
On the other hand, there were plenty of 2G-only low data users around, so retiring that early would break stuff for a lot of people. Keeping it around longer gave people more time to upgrade.
I think the reasoning was that the heavy data 3G users had already upgraded to 4G and beyond, and low data 3G users could fall back to 2G, so retiring 3G would have negligible impact - while opening up a lot of bandwidth for 4G and 5G.
On the other hand, there were plenty of 2G-only low data users around, so retiring that early would break stuff for a lot of people. Keeping it around longer gave people more time to upgrade.