Dark Funeral are very much like the AC/DC or Korn of black metal; they know their sound. They know it well. The understand their genre well. They understand well what the fans of said genre are looking for. So why deviate from the norm? They can just make the same low-effort redundant stuff they've been making for 20 years and us black metal fans will come back to hear some well-played black metal. Why not? When they can come up with the same fast-paced riffs and raw, unhinged vocals and satanic lyrics, all neatly packaged in the same song structures that they've stuck to for 20 years, why should they try anything deeper? Hell, it works well for them, so sure, stick to it. That said, you may think that I'm saying this all inherently negatively, but honestly it's just a fact that you get used to that there's always going to be that derivative artist in a genre who happens to be pretty damn popular, and y'know what? Sometimes it's fun to just chill out to the most generic stuff out there instead of listening to the boundary-pushing, ever-evolving ones. Dark Funeral are never going to be seen as one of the kings of black metal. They're never going to be anyone's favourite, and they're never going to make their Transilvanian Hunger, Filosofem, De Mysteriis, Nightside Eclipse, etcetera. They've already made their peak half-a-dozen times, and that's enough for them. And that's fine.
I do need to wonder why these critics are just letting a veteran band who haven't evolved a single inch in their 20+ year long career get away with yet another decent-at-best and unbelievably predictable release so late in their career though. Guess they just get a veteran pass, but at the same time this is getting far too prevalent even for newer bands.