I think some of those substances can have positive in a very narrow set of circumstances. Being vigilant and only using them in those scenarios can be just as hard as the hard solutions you were avoiding in the first place, like sleep, diet, exercise, cleaning up your routine, etc. I'll add some color on how some of those can go wrong, hopefully this saves someone else from having to learn it first hand:

Alcohol - messes up your sleep, without which your mind will never be operating as clearly as it could. If you frequently mix it with other substances, it'll also turn into a trigger, making you crave said substances every time you have a drink. Use with moderation.

Shrooms - these are really nice, but like most psychoactive substances, they'll definitely get in the way of focusing on hard tasks. Doing something fun gets more fun with shrooms, doing something hard gets harder. Use with moderation. Indulge, don't escape. I'd give the same advice about LSD.

Ketamine - has an extremely broad profile of effects depending on dosage. You can mitigate this a bit by correctly measuring and dissolving it in nasal spray, but even then tolerance builds up very quickly and you end up compensating by doing more. It has a small dosage window where it'll be an indulging drug, just adding a pleasurable shift to your perceptions, but then as soon as you go over that window, it will turn you into a little dissociated zombie, unable to hold an interesting conversation with someone who isn't on the same ballpark of high as you are. It can cause serious damage to your urinary tract. Indulge, don't escape. Try to use once per month at most.

MDMA - can be amazing at low dosages, but evidence indicates it is neurotoxic in most doses you'll run into in parties. When it starts to come down you will want to do more, so if you're trying to be careful make sure you have measures to prevent you from doing so. Hangovers can be brutal, specially on higher doses. At higher doses it'll make you confused and mess up with your short term memory, but your social confidence will still stay high, so you can turn into an obnoxious person rambling about something for the third time in half an hour to whoever is unlucky to be nearby. Indulge with a lot of caution, don't escape. Use lower doses. Give it a 3 month break between uses.

Research chemicals - unless you are the researcher, stay away from these. Some drugs have very different effects to others that are chemically very similar and often impossible to differentiate with standard test kits you'll be able to buy and use without being a chemist. Reliable information on their effects, dosage, interactions is difficult or impossible to find — not only for you, but also for your EMT or doctor, in case you need medical assistance.

Uppers - addictive, can cause re-dosing, will fuck up your sleep and your appetite. Suppress orgasms (and often erections). Stress your heart muscles and your arteries and veins. When taken for productivity, will give you short-term gains that turn into holes you'll need several weeks to dig yourself out of. Use with extreme caution.

Amplifier substances - in my experience, there's no such thing. You can do substance X today and have an amazing "amplified" time, and then do the same dose again a week later in a different setting and have a real bad time, constantly in your head, seeing the negative interpretation of everything. The things which make it more likely for a substance to be an amplifier can't be fixed with more substances: how well are you sleeping, eating, exercising? Are you mulling over some difficult conversation instead of just having it? Are you surrounded by people you like who are good to you?

while they do have therapeutic effects (some, I wouldn't say alcohol does), I don't think they should be proposed as methods to relax stress. Too many downsides and are not sustainable as regularly used substances. Yes you do feel great in a night of MDMA but the feelings you have the following days almost negate the positive aspects.