Deuteranomaly causes difficulty distinguishing between shades where the precise amount of green is relevant (i.e., to a deuteranomalous person, pure yellow -- equal parts red and green -- would still look slightly reddish-orangish).
Protanomaly causes a similar effect with red, and also dims the dark/deep red part of the spectrum slightly.
If someone doesn't want to use the medical terms for them, better names are "green weakness" and "red weakness" since they don't carry the misleading "can't tell red and green apart" connotation.
My brother-in-law and I are both colorblind (mine is not as severe as his) and he bought a pair a few years ago. He enjoys the difference but not enough to wear them consistently, and they had a barely perceptible effect on my own vision, just giving green a bit more "pop".
I think the main issue is that it's easy to group all colorblindness together even though "huh, I guess my shirt really is purple" is very different from "I look at streetlight positions, not colors."
That said, even my mild colorblindness puts me at a massive disadvantage on certain Halo maps or against certain team colors. In situations like that, I might as well be fully colorblind asI end up having to play based on movement alone.