wouldn't that break progression if you have everything right away anyway ?
Doom Eternal has huge replay value. When you go through, you get weapon points which unlocks upgrades when you find the weapon mod robots and then you unlock mastery challenges which allows you to max out your weapons, using the weapon mods are fun and some you don't get to unlock until near the end of the game.
You can also find secrets and locations they have cheat codes for when you want to play through. To lose your save and not be able to replay the campaign to experience these maxed out weapons and have fun with the cheat codes such as unlimited ammo- it sucks.
For the next gen version, it will be my 3rd play through of the campaign so not having my save and have to grind all that again is absolute bullshit. It means nothing for people who don't care about the game or like the game but for some people like us its a huge deal.
This is why New Game+ was invented on games, so you can play again with the skills and unlocks you already have.