Here's the deal.
Because of their nature, there are several ways to get light out of LEDs. One can, quite literally, just string them together and plug them into the 60Hz outlet. They'll flicker at just the right rate to cause headaches and nausea, and that's how a lot of the cheapest lights are done.
One can also build a super-cheap power supply for them which eliminates the flicker entirely and produces a very clean and pretty light.
Just, the super-cheap power supply still adds a few pennies to the cost - and the lowest price brands aren't into spending one-hundredth of one percent more than they absolutely must.
Every time, every single time a new technology comes along, somebody is going to latch on to the worst, most primitive aspects of it and decide that that's the way it was, is, and ever shall be. We had this same discussion back in the early 2000s about CFLs. This.Exact.Same.Discussion.
Look - if you're using a smartphone or a tablet, monitor or laptop built after 2015, you ARE looking at LED lighting. And it's not giving you a headache and, no, you can't tell'.
Goodness.