Yes well this forum covers not only psychedelics but also dissociatives, deliriants and other odd ones, we needn't quarrel about the semantics.
Each substance or family of substances similar to each other in effect has its own dangers and advantages. Generally speaking, but also for beginners.
Not everyone may agree on what is advantageous, but by comparison if a drug immobilises you that can make it safer to explore inner worlds. Considering dissociative drugs, immobilisation via anaesthesia can matter a lot for the course of a trip. Especially for someone who is not sure what to expect (without a frame of reference), physical safety partially depends on what you are actually doing versus what you think you are doing. If physically you are doing nothing because a drug makes it almost impossible to walk or navigate any space, that can be an improvement of safety compared to say a person who becomes delirious on 2C-T-7.
Other drugs such as 2C-B, 2C-D or 2C-C - the rather easy side of phenethylamines - have quite different advantages and disadvantages. Usually there isn't much immobilisation or behavioral dysfunction (I am talking reasonably low dosed). But in my opinion, that is not really necessary.
Which brings me to another issue which you apparently focus on here: mental safety.
Classical psychedelics have an all-round effect profile: they can do most of the things psychedelics can do and compared to some other psychedelics those effects are relatively spreaded or balanced. But they can be strong. Beginners should watch their dosage, set and setting for sure. That is always the case, but the 2C drugs I previously mentioned can be more forgiving in that respect.
I don't find DXM particularly safe or ideal for beginners, the effects are very varied in the sense that a group of people find recreational, entheogenic and psychedelic value in it while others like me experience a vast amount of confusion, memory loss and other side-effects with it. In my opinion the drug's effects profile is not a clean one, and the fact that a considerable part of the population has the appropriate tolerance for the side-effects does not really change that in my perspective. Surely, some people find DXM special and they may keep coming back to it but the hit or miss quality is not what I appreciate for a beginner.
Beyond that, I don't see what point can be proven discussing what 'kids should jump in with', if the choice is between LSD, ketamine, DXM, psilocybin, or another hallucinogen, except that any of them can be devastating if taken to far and what is valuable for a beginner is something relatively consistent and trustworthy if approached with care. It is typical for hallucinogens to be unpredictable compared to say amphetamine... but I would choose a mild phenethylamine or mild tryptamine for a beginner over DXM any day of the week.
Shall I merge this with the Psychedelic Beginner Thread? (Probably not considering the emphasis on DXM?)