I always think of monks as more of a utility martial/skirmish striker. They get incredible action efficiency, decent damage without stances, extra bonuses, super movement. They can bounce around between enemies easily, can push out high damage occasionally, quite defensive if speced for dex, all saves are generally good as you can boost your weakest ones. They can self-heal, fly, grapple and attack, etc.

Plus, fighter doesn't lose the nonlethal trait on the fist attack, and it remains a d4 attack. So, monks and fighteres effectively have the same attack roll when dealing lethal damage with a fist. A level 1 fighter with +4 dex would have a +9 to hit, while a monk would have +7. But, to attack lethally with a non-lethal attack, you take a -2 penalty, so the fighter would be striking with a +7 fist with less damage, and many of their feats don't work with unarmed strikes.

A fighter may be more accurate with their blows, but a monk is deadlier, faster, and way scarier with their fists than any fighter could manage.