Are unsafe attacks necessary in combat systems?
I have been studying a lot of combat systems across various genres of games, and from those that I have seen, having unsafe attacks seems to be quite a common staple. But I am not sure why? I think I understand the concept/purpose of unsafe attacks as a mechanic in a combat system; it essentially boils down to a risk vs reward system right? In order to balance an attack and prevent it from being overpowered the risk of it being unsafe is introduced, so if you get it right you reap a huge reward but if not you are hugely punished. In counter, an attack that is less risky reaps an equally less significant reward.
I suppose another way to pose the same question is, what effect would it have on a combat system if all attacks were made safe? For example would this make the combat more offensive/defensive focused as oppose to being an equal balance of both? Do games with such combat systems even exist?
I feel that adding a sprinkle of reality onto this concept may shed some more insight into why I find this mechanic slightly confusing. I am happy to be proven wrong, but my understanding is that in real life a skilled combatant (of any discipline) would never intentionally attack with a move that they know is unsafe, yet from what I have seen many games feature player characters with a plethora of unsafe attacks. Doesn't this go against the narrative that this is a skilled combatant? Another example is the basic jab; again happy to be proven wrong but my understanding is that the purpose of this is to create momentum for the attacker, hunt for an opening and be able to rely on this as the fastest and most safest attack in their arsenal. Yet so many games have jabs be unsafe on block. Why?
Hopefully I have explained my question in enough detail but if not please let me know what is missing and I'll be happy to add it. Thank you and looking forward to some insight on this part of combat systems.