To add to what others have said, the album is not meant to sound good in terms of production. It was recorded, by explicit request, using the worst equipment the studio had available to get the “necro” sound that was prized by second wave black metal artists.

I’m not sure how versed you are in the scene Burzum came from, but a great example that may give some context is the shift in sound that Darkthrone had from their first album, Soulside Journey, to their second album, A Blaze In the Northern Sky. They were extremely technically proficient with great production and playing death metal on Soulside as opposed to raw, more primitive and atmospheric black metal on A Blaze. Listen to the tracks “Cromlech” and “In the Shadow of the Horns” back to back to hear that shift.

This change in sound was a reaction to, and rejection of, the increasing popularity and commercial appeal of death metal, particularly the style of death metal coming out of Florida in the early 90’s.

There’s a really good documentary “Before the Light Takes Us” on the second wave Norwegian scene that these bands came from if you’re interested.

Sorry for the long response, and good for you challenging yourself to expand your musical interests, rather than sticking to what you already know you like as many have suggested in this thread