Often much less in practice: 2G transmission was up to 2W, but 2G has been phased out in many countries. 3G I'm not very knowledgeable but IIRC was up to 800 mW

Often much less in practice: 2G transmission was up to 2W, but 2G has been phased out in many countries. 3G I'm not very knowledgeable but IIRC was up to 800 mW (common case). LTE/4G is 200 mW maximum for sure. 5G is the same except for mmWaves, but that I don't know very well and it's not used much (not at all in Europe, where I live). There are more powerful band classes, but for fixed wireless access. So for phone use on a modern network, you should now be most of the time at 200 mW max transmit power (same as WiFi BTW).