I love (half)slips, you just have to watch out that the sewn-in lining of the skirt or dress doesn’t fight with the slip. Occasionally the material of one makes the other bunch up or twist. Perhaps the lack of slips these days reflects that skirts and dresses are now lined more than in the past?
I also wear a camisole to smooth the lines under my blouse if I have a half slip on. I also use full slips at times, especially when wearing a full dress. The slip helps the dress / skirt move better on the body and hides the sharper edges of the male form!
The more expensive lingerie makers still sell full slips and camisoles, half slips are harder to find.