For years wall lights meant one thing: a boob light in a hallway nobody updated since the Carter administration, or those brass picture lights that made everything look like a hotel lobby. That has genuinely changed. The options now, especially the plug in kind that need no wiring at all, mean you can put real light exactly where you want it without touching a wall cavity, and that shift from electrician job to weekend project is the best thing to happen to this category in a long time.
They do their best work in living rooms that get dim by four in the afternoon in winter, flanking a sofa where a floor lamp would just get kicked, or either side of a fireplace where symmetry makes everything feel more finished than it is. Older apartments with low ceilings and one sad overhead fixture benefit the most, because wall lights give you a second and third layer of light at a height that actually flatters a room, instead of flooding it from above. They also suit smaller living rooms where floor space is the whole problem, since the light hangs on the wall and takes up nothing on the ground at all.
On finish, matte black and warm brass have been the easiest things to live with in every rental and every house I've seen them in, because they read as a decision rather than a trend, and they don't show dust or fingerprints the way polished chrome does within about a week. If you own none of these yet, start with a plug in swing arm version in one of those two finishes, somewhere near a sofa or a reading chair, and live with that one light before you commit to a pair. It tells you fast whether you actually want the light there, and whether you want warm or cool bulbs, before you've spent money on a second fixture to match a decision you're not sure about yet.
In an ordinary room they sit well next to a reading chair with a low side table under them, holding a mug and a book without competing for the same surface a floor lamp would need. They also pair naturally with a mirror or a few framed pictures nearby, since the light throws a bit of a glow across the wall itself, not just downward. The honest limit is that most wall lights throw a narrower pool of light than a good floor or table lamp, so they're a layer, not the only light in the room, and if you're relying on just one for an entire living room you'll be reaching for the overhead switch by eight o'clock anyway.