Adding to what others have said, I also find that DXM has been the closest to MDMA's rolly euphoria I've experienced. The euphoria came in waves, similar to MDMA, but was utterly overpowering. I was drowning in pure hedonistic euphoria. This only happened once when mixed with THC and I've never used the combo again. I had some pure DXM powder lying around and decided to experiment with it recently and it just was not the same. Empathogenic qualities were still exhibited but not the obliterating euphoria. The drug starts to become dysphoric when abused in high doses frequently and feels heavy on the brain.
I think the least harmful alternatives are phenethylamines that are closer to the psychedelic spectrum like 2c-b. From my understanding, the more stimulating substances tend to have a worse safety profile and are less sustainable in the long term. I've heard good things about 5-MeO-MiPT and 5-MeO-DiPT though I've never tried the compounds myself. The blue bliss pellet is supposed to recreate the feeling of MDMA with less toxicity. It contains 5-MAPB, 2-FMA and 5-MeO-MiPT. Methylone was developed as an MDMA alternative with less toxicity.
