If you include indonesian dishes (rendang, coconut type curries etc) in your stews category, then browning isn't an essential step. Meat is not browned first in indonesian cooking in my experience, I'm on the fence as to whether that detracts from the taste or not as I've never tried it with browning. I'm not allowed in the kitchen when my wife is cooking!
With western style stews though I think browning is an important step: I did a shin of beef stew in the slow cooker over the weekend in a hurry and it wasn't as good as if I'd have browned the meat first.
I'm a little weak on what the actual definition of a stew is, but rendang is chunks of beef that's cooked for a long time in a little liquid, so I guess that's close enough!
A braise is a slow wet cook of (usually) large pieces of meat (but short ribs are small, as are chicken thighs).
A stew is a braise where the meat is cut smaller, as if for a sautee, and where there is more liquid than meat.
The same cooking process is at play in both: long, low, slow, water-modulated breakdown of collagen into gelatin, with the liquid absorbing flavor and proteins from the meat and also melding all the flavors from all the ingredients, producing either a sauce or a soup in which to serve the meat.
I totally believe there are cultures that don't routinely brown meat before stewing, but they don't include Mexican, French, Italian, Spanish, Indian, Thai, or Chinese. Look up a beef curry recipe in David Thomas' Thai Food book, or a beef tendon stew recipe in a Chinese cookbook, or a lamb curry recipe in an Southern Indian cookbook.
Browning meat in a stew serves the same purpose that the fond serves in a pan sauce in French cooking. The maillard process creates objectively delicious meat flavors, which are then absorbed into the liquid.
You are right, a lot of Asian cuisines rely on other strong flavors like fish sauce, tamarind, seaweed, and fermented pastes. With these you will not miss browning. You know you have learned how to cook Asian food when you can make delicious meat dishes without browning.
I have well-regarded Indian, Thai, and Chinese cookbooks, and they routinely brown meat for braise and stew dishes. I'm curious why browning would ever be a bad thing in a dish that uses tough meat (ie, stew meat).
I absolutely believe you that there are authentic dishes that don't rely on browning for flavor. I'm just curious what they are.
Off the top of my head adobo and many Korean stews like kimchi and pork stew (Dwaejigogi Kimchijjigae). Browning isn't a bad thing, you just don't need it for all dishes.
With western style stews though I think browning is an important step: I did a shin of beef stew in the slow cooker over the weekend in a hurry and it wasn't as good as if I'd have browned the meat first.
I'm a little weak on what the actual definition of a stew is, but rendang is chunks of beef that's cooked for a long time in a little liquid, so I guess that's close enough!