As many people said now, there has to be a balance between realism and gameflow. Nobody wants to restart the game once they get a fatal injury (unless in a “hardcore mode” - hold that thought!).
If you saw the fight in the 1 hour gameplay video, you might have noticed that the character was stabbed in the chest like 5 times. In my opinion thats way too much damage to continue fighting and still keep the game feeling “good”. If you managed to get stabbed 5 times, you should have to reload.
Only my two cents.
A good substitute for realism without making battles be about carrying the most number of healing items possible is to use impact damage which very few games adopt but it has been done before. Basically every strike deals a healable and unhealable amount of damage where the unhealable damage is only restorable by beating the level, in this case probably sleeping. So extended combat becomes more difficult the more wounds you take, but you can still get it all back by getting completely out of battle situations and going to bed or a doctor or something. And you can still recover from little screw ups between fights here and there with recovery items. Realism is good and all but there is a point where you can take it much too far.
Honestly, I think health regeneration is bad thing - It removes challenge and feeling like you really have to look for your character.
Look at modern fps genre - you take 5 bullets and after 10 seconds you are full heath again. For me it turns game into brainless runaround.
But there are genres which did it right imo, like Stalker series. There’s no health regeneration - you have to apply bandages or eat for health to slowly regenerate. Mods were made where you can even sleep in your sleeping bag to regenerate health, but you also have hunger meter, so you have to eat after a while or your stamina would be draining and you would always walk slowly, instead of running.
There were antiseptics and natural antibiotics. The usual wound dressing was Sphagnum moss, known for being absorbent and having sterilising properties. “Modern” pain relief was available in the form of willow bark extracts (Aspirin).
It is common to find skeletons with serious bone injuries with evidence of substantial healing - re-sealed skull fractures or fused breaks in long bones being present in a large minority of skeletons recovered.
Don’t doubt it at all - the reality though is that fractures provided they didn’t break the skin are unlikely to induce infection. In Western medicine at that time the cause of infection was obscure (people didn’t know about bacteria and few actually knew about basic hygiene). The fact that some recovered from injuries does not mean that the infective risk is not there and that deep penetrating injuries would not result in a slow agonising death for a worrying majority of people. We can’t really have a realistic injury system unless we put up with a long recovery (12 weeks for a leg break with the risk of permanent disability as a result) or easy death from injury.