Realizing that TOS was just what they had the budget to do at the time, and was not close to how Gene or others would have wanted to do it, is the crucial first step in ridding oneself of obsessions with "canon" and "continuity."
I'd actually say in 1966 they made it as they wanted it for a TV series of the day that expected to be forgotten once it ended. I doubt they sat around and lamented not having the money to make it look "better." They weren't making a feature and they certainly weren't concerned about how it would look 60 years hence. I take everything Roddenberry said about TOS after the fact with HUGE grains of salt.
When they DID make a feature, yup they updated it because it was a TV show with a limited (but still generous for the day) budget and a gazillion dollar motion picture on a MUCH larger screen needed to to be updated. What didn't they keep the design closer to the TV series? Easy: not because it looked bad, but because the novelty of color television was over and irrelevant for a 1979 movie. So the colors were muted, but the overall design was retained. Styles of what the future may look like changed dramatically in 10 years, so the sets had to reflect that. Everything changes. It would have made more sense in universe if they said 10 years had passed and not 2. It would have also explained why everyone LOOKS 10 years older. But they wanted it to be sooner, so visually it's a more drastic change.
Not every change or update is made because the original is somehow "bad." Out of date isn't a bad thing. Technology movies forward, styles change, and if you're going to appeal to a modern audience, you have to make updates.
I prefer the SNW Enterprise to the Bad Robot version, but I still wish the sets were less cavernous. A smaller bridge with a viewscreen other than a window would have been my preference. Other than everything being supersized with a smaller crew than Kirk had, I like what they did with the sets. They are very tastefully updated versions of the original designs. And I love the hand props like the communicators and phasers.
The TOS bridge looks fine, but there are obvious things that stand out, like the wrinkled paper viewscreen displays over the science and communication stations and, yes, some wood grain. But by and large, it DOES hold up - but it's still dated. Just like a 1969 Ford would be. It looks great, but it doesn't really fit in today's world.
It doesn't bother me any more than the original effects do. It's not Nostalgia Glasses but it is "watching in context." My mind shuts it off because of the age of the production.