Techniques to Remove Water from Vegetables?
Ordinary drying/dehydration can certainly change the taste and texture of foods, but the primary point of dehydration is often preserving food rather than improving taste.  Sometimes additional seasonings are added during the drying process (as in beef jerky, although I know you were asking about vegetables).

Application of heat often releases liquid from vegetables.  For example, wilting spinach or other leafy greens on the stove top, or roasting root vegetables in the oven.  Especially with high heat, as in roasting, other chemical processes are creating flavor besides simply removing water.

Osmosis is a another process for removing water.  For example, in making namasu, it is common to sprinkle salt over thinly sliced cucumber and let it sit for 10 minutes to several hours, sometimes with a weight on top
to help press out liquid.  Then the salt is rinsed off, leaving little salt taste but a large change in the texture and flavor of the cucumber.  Add vinegar to this process takes you into the realm of pickling, where some of the change to the vegetable is from removing water but some is from infusing other flavors.