For me it’s a good thing to do if it’s to match the singers range - a good example of this was in The Dirt, the band started Live Wire in regular tuning and the Vince wasn’t getting it, so they detuned to D and suddenly it was there.
But I’ve found that in the songs which I play with a low D even the higher notes on that string just sound wrong to me.
One gig I did the singer had throat issues so we dropped to Eb, and I found it horrible, just couldn’t get the pitch right in my head.