My Samsung S21 running the latest Android (13) doesn't offer the option to disable 2G while keeping 4G/5G. The list is literally: 2G/3G/4G/5G, 2G/3G/4G, 2G/3G, 3G only, or 2G only. If you want to keep 4G and/or 5G you're SOL. Personally, I would prefer 4G/5G (as the 2G/3G fallback on my network next to useless outside the 4G/5G coverage footprint). Hopefully when Android 14 comes to the S21 it comes at least the option to disable 2G as described in the article.