I honestly think the new loot system is terrible. I'm trying to think from the perspective of a realistic and fun approach to how looting would look like in this post-apocalyptic world. It's pretty lame finding a military style ammunition crate that only gives you some @%$*#!ty spears or low level trash because you're only on game stage 5. This is immersion breaking in my opinion. I've noticed looting is almost linear and not random at all, you know what to expect, and it almost makes looting pointless because I'd rather save important crates or chests for looting in a different game stage because I'll just get another 5 spears. Of course you can still get useful materials such as duct tape, oil, etc. But in terms of getting weapons, tools, and items with levels, it's poorly thought out and doesn't have that randomness and excitement to it anymore.
I know this would be complicated, but I think there needs to be a more realistic approach, for example looting regular homes should give you loot that you would realistically find in a home, so basic stuff with a small chance for weapons. The challenge to make it through a home POI should be easy since it's a place that maybe doesn't have a high yield. But if you decide to go to a military base, then you should expect a challenge and be rewarded no matter what stage. I know this sort of system would also have its issues due to players cheesing zombies or whatever at low levels and then getting epic gear, but I still think some sort of realistic and intuition based approach should be used, and not this game stage based looting. I do not like this new loot system, and prefer the previous style despite its flaws as well, but at least it still felt random and there was that feeling of excitement and not knowing what you were going to get. There is no excitement or mystery in this new system.
Sorry, not a very well thought through explanation, but I genuinely do not think this game stage looting is the proper approach. I feel like there should be that tiny chance of finding maybe a higher quality weapon during the early stages, but it should be impractical to use it in the early stages of the game.