I would be complaining alot more about the lack of option to pick varient human as a race over darkvision for the few races that do not have it you can also use spells to off set this by casting things like light on your items ect to counter balance it. Its not disbalanced enough to matter. Its something that should factor in as to why you chose a race of a class. There are pleanty of fights out in the open above ground that are not hindered by this but if your in a cave underground ect it should be a factor in as to why you chose a race or class. I generally pick races with dark vision because i dont like carrying torches however if they had varient human it is not enough of a reason for me to not chose the race as an option if it was present. However there is also the lack of feat options currently that are not the most impressive as more half feats would make this far more enticing for the varient human as an option. When I am choosing a race in actual 5E I dark vision is one of the things I take into consideration when choosing the race. As it is there for a reason.
