mmm I think you make sense but at the same time you are taking things too literally... lets keep calling them "alchemists" lol there might seem like there are a lot of them but there are not really, his master was the last "great alchemist" and the rest cant be considered "pros", maybe the last apprentice of his master, and under him some of his teachers... but not even them completely succeeded, is like with practitioners... there are a lot of them learning martial arts techniques and you can call them "martial artists" but that doesnt mean they are the same as those who get "respect"
Then just take a loot at the earlier chapters, when that first green haired alchemist showed up to financially ruin Xiao Yan's family. He was a mere 1 star alchemist that could make basic powders, not even proper pills. Yet he was already being treated like royalty. It's always other alchemists that get treated with great respect or fear, but never Xiao Yan. He's always "trash" or a "nobody". Yet he can create 7th grade or higher pills now. An alchemist that even elders of major, hugely rich and powerful families should desperately seek to make friends with. But once again, except when it's Xiao Yan...
but that's the point, you could be the most powerful guy in the world but if no one knows about your strength then you won't get the proper recognition, if he wanted to be recognized he should have stayed in school, keep going for competitions and obtain a proper "title", he doesnt have the reputation he deserves because he never achieved it
I quite like this manhua, but I have to say the world is kinda inconsistent. I just started rereading from the beginning, and in chapter 8 it's mentioned that alchemists (not going to deal with the word used in the manhua. :P) are supposed to be feared and respected. That even royal families wouldn't dare offend a high class alchemist. Yet Xiao Yan is definitely at that level by now, being able to make tier 7 pills and the like. And others still constantly say he's trash.
Furthermore it was also said that in the entire country there were only tens of alchemists. Yet it feels like Xiao Yan alone already encountered more than that by now. Like at the academy, there was an entire club filled with lower ranked alchemists.
Sure, I get that the MC needs obstacles to overcome, but in that case the author shouldn't have set up how "respected/feared" and "rare" alchemists are supposed to be. He could have just made it so it's hard to become one, but not rare