I dont want to sound harsh ... but maybe i will so i just state in advance that its not my intention.
It seems like nostalgia dreaming to me ... you know the kind old people have when they say that back in their days everything was right and better ... grass was greener, sun was warmer, politicians were honest ... that kind of stuff. I mean i get it, kinda ... i also dislike what happened to my favorite settings (including games movies and books) but you cant stop progress and it just require changes ... only time will tell wich change will be remembered or fogotten.
Now lets look at sone specific points: You were complaining about races ... i dont understand what should i take from that ... its somehow bothering you that there is more than just elves and humans?
Take Gith ... there are 4 in that cinematic as far as i know (including Lae'zel) and yes we later meet their patrol of 5 plus Kithrak if i remember corectly. Thats not so much in my eyes. O_o Also it kinda make sence that if your story include some cteature (a mind flayer in this case) you cant and possibly will also meet their forsworn enemies.
Tieflings being more common than humans ... this is just wrong observation ... i mean you are ignoring context here, you said it youreself we didnt even reach any settlement so far and as they tell us they are not even from here. It makes to me as much sence as claiming that there is more Asians than Black people in Africa based on that you meet Chineese tourist group on airport. :-/
Companions ... well that is its own topic ... but are they really so special? Lae'zel > totally regular and kinda boring among her own people ... i mean she is not even concidered adult. all her specialness is that she separated from her flock ... isnt that the oldest story ever made? Gale > i mean i can understand that he would seem little too much, banging a Goddess of magic herself is no small feat ... i must admit that i dont know how often Gods walk among meere mortals in this world ... but concidering that almost litteraly any cleric can chitchat with them, it just seem possible ... also as far as i know we were told that Gale loves her but not even a woed about hwr feelings ... i mean have you heard about Zeus? The guy who created basicaly whole Greece mythology bcs he had some bed adventure with mortal from time to time? I dunno why Gods so often have fetish for humans but concidering varoety of halfbreeds they are not the only one. Astarion > only a spawn ... and Vampires are not uncommon in this setting ... so where is the problem? I mean yes he gets quite strong bonus action (i really wonder if that gets powerup in level 5) but except that? As far as i know vampire mind flayers are rare but not new in this world. Wyll and Shadow are just regular persons in my opinion.
But i dont want just criticize ... I agree woth your point about scrolls and enchanted things being little too common ... But personaly i believe (read as: hope) that this is just for EA purposes to find out vich magic effects people like.
It all boils down to preferences if i see it right.
Back when D&D was new there were no tieflings, or genasi. And if there was a race like this, it was never intended as player race. i guess that most of this feeling the OP (and me at times too) comes from the fact that we encounter monsters that are usually expecteced at a much higher level.
I am with you on that "in my age everything was better". I really hate that too. Maybe "in my time i liked everything better" would be a better way to put it.
My only fear is that when you start off on such a high and epic level, with mindflayers and so on, you have to keep a high level. Who wants a story to get boring later on? Hope they did not fire most of their powder.
also, regarding the lore i know, mystra making contact to humans is not that rare . but why go after a fop like gale? :P
all her specialness is that she separated from her flock ... isnt that the oldest story ever made?
. but why go after a fop like gale? :P
