> LEDs must be powered by a constant-current supply, and distribution does not work well at constant-current, and is always constant voltage. So no matter what you will need some sort of switching power supply.

I think the biggest problem is that many cheap power supplies cycle at lower frequencies that cause flickering which is perceptible subconsciously. A modern switchmode power supply might operate in the 50-500khz range which will not cause perceivable flickers.

The really cheap stuff actually doesn't even have a power supply! There's a breed of LEDs that takes straight AC and rectifies it using the LEDs themselves. By using a large number of tiny LEDs in series (typically in COB form), you can easily reach close to 110v or even 220v, and then you add a small current limiting controller in series that's dirt cheap compared to magnetics... These are super cheap, and appear bright, but they flicker at 120hz, which can be annoying when there's motion or if you're sensitive to it.

I'd say it's a very bad choice for a bedroom or living room light, but I have nothing against it for the outdoor lights, signage and a bunch of other applications where cost is king.

I have a serious problem with it for outdoor lighting and signage: it gives me a headache. Enough exposure will make me feel actively sick. The effect is not subtle.

Just don’t use these devices, please.

Branding matters. If your brand is a light that flickers, you might want to consider the old adage penny wise, pound foolish. As a consumer, why would I choose to shop at an establishment that has flickering lights when I could shop at a different one that did not? Unless of course, I had no choice.

But then, a wise entrepreneur would recognize paying extra to have non-flickering signage would attract some customers.

Flickering lights can induce migraines in susceptible people, so literally, saving a penny here actively drives away business.