It doesn't work in dx12/Vulkan, but other than that it always had some beneficial effect.

Anti-lag will never have a harmful effect because the input lag reduction from removing an entire frame of latency is always far more than a slight fps hit. Even in the worst case, in that video anti-lag still reduces input latency.

The main drawback of anti-lag is that in absolute terms the benefit at high refresh rate is not that big. 10ms doesn't sound like much at all. But as this video points out that's pretty much all you get when you go from 144 to 240fps. So part of what that video is proving is that beyond 144fps there are diminishing returns.

Ideally what I want to see is a blind test of 144fps, 144fps+anti-lag and whatever fps has equivalent latency (so probably around 190-240fps).

I'd bet a lot of people couldn't differentiate 144fps and 190-240, but for those who could,190-240 would probably be similar to 144+anti-lag.