The Enterprise blu-rays are pretty disappointing. At least, the first 3 seasons that were shot on film. The last season was recorded digitally with the cutting edge HD TV cameras of 2004 and somehow that looks better than the stuff shot on film.
They apparently didn't want those earlier seasons shot on film to look like they were shot on film, so it's all denoised very badly. It's hard to tell compression artifacts from denoising and smoothing artifacts. Combine that with the early 2000s bloom that every TV show around that time was caked in, and the generally flat color profile of the whole show... it doesn't look very hot today. Somehow manages to look much worse than TNG from 20 years before.