It was stupid for them to do that and created a lot of problems. I'd like a scene where all variations are in a room and no one takes a moment to say anything stupid. Klingons are Klingons.
That would actually be an awesome explanation.
But yeah sure Klingons can look different from one an another. That's why they have different forehead patterns, skin tones, etc. TOS and DSC Klingons look like... an entirely different species. ENT gave us a reason for the TOS Klingons, DSC Klingons are still baffling (even to DSC and SNW... who clearly moved away from the initial design immediately).
I'm actually ok if they did just start kind of... using all of them interchangeably. Makes it weird that we only see on particular "race" at a time, but whatever.
I love PIC's answer to the Romulans... "He's a northerner", referring to the ones who just look like Vulcans. Cool. Honestly I didn't even particularly need an explanation for that, but it was cool they did it.
I do understand it had explain the incompetence done on DS9 where the classic TOS Klingons looked like TNG versions. It was stupid for them to do that and created a lot of problems.
It created ZERO problems.
What created problems was making a new show, yet another prequel for no particular reason, just to change them
again... and also for no apparent particular reason.
I can understand not making everything look like the 60's. I don't like it, but I understand it. But the Klingons... if they just used the TNG+ Klingons, it's fine. What was wrong with that makeup? Nothing. Does Worf look super dated in PIC? No. It looks fine.