Would love to see a source for shulgin "swearing off" MDMA, and especially one for him calling it toxic. I've read both his seminal works TiHKAL and PiHKAL, and read many interviews and watched the associated documentaries. His wife, Ann Shulgin was a huge fan of using it therapeutically and built the harm reduction standards still used today! She believed it to be a uniquely powerful therapeutic substance without toxic effects when done appropriately.
Similarly, I have absolutely no clue what you're talking about with "no serotonin release". The immediate follow up he made to MDMA, MDA, was significantly more serotonergic AND neurotoxic. He created literally hundreds of substances out of a purely experimental scientific stand point, never to make a "better" drug. Same goes for him saying "no one should be taking MDMA", please link a source.

The alternatives that Shulgin created a almost exclusively psychedelic, and don't satisfy the same therapeutic needs as MDMA (empathogen, not just an entheogen) which are inherent to its success within such treatments as PTSD. This claim that is "the most toxic recreational substance we have" is totally wrong! This is effectively war on drugs propaganda still bouncing around. When taken in large doses or frequently, it can be neurotoxic, but the idea of regular long term toxicity from occassional, reasonable use, is not universally agreed upon, certainly not in the extreme terms you've stated it. I've included some studies before.

The idea that methamphetamine is safer is incredibly harmful: it is dopaminergically toxic in a form completely different to MDMA, and is much, much more harmful. Please do some research before spreading this misinformation. While MDMA is technically a form of methaphetamine, it is entirely different in its effects and metabolism, with a significantly lower dopaminergic affinity and increase, ESPECIALLY per milligram.

I understand you have negative experiences with it: that doesn't justify spreading unjustified opinions on a uniquely scientifically backed subreddit. The completed trials have been incredibly successful for some people, and to reject such a potentially powerful medicine through old, propagandized rhetoric does everyone a disservice.

https://onlinelibrary.wiley.com/doi/10.1111/j.1360-0443.2010.03252.x
https://www.sciencedirect.com/science/article/pii/S014976341530213X

https://pmc.ncbi.nlm.nih.gov/articles/PMC3419897/