I remember when the 3DS was region locked (cartridges can only be read if the console is bought in the same country those games are from) meaning it’s a headache having to switch between two variants of the handheld (I had a Japanese 3DS XL and an American 3DS regular back then, alternating on each one depending on which game I wanted to play). The switch alleviated this by making the cartridges / console region free.
Biggest headache is to make sure your country is following what region if you’re not anywhere near those region. Like US region consist of the whole America(make sense), but for some reason also include Saudi Arabia and UAE(should be EU as it’s closer), and Singapore and Malaysia(should be TW as it’s asia and closer), while HongKong is with TW alongside Taiwan(where HongKong should be with CN but i guess this one makes sense as HK is autonomous region before the recent crackdown).