I agree with ninja. I picked deep gnome for my first playthrough (directly went for tactician) and I was quite disappointed that my superiour darkvision almost never mattered. I had Lae'zel in the party the whole time and in the entire game there were maybe three fights where not having darkvision gave her a disadvantage.
In my opinion, given the powerful items and the fact that we can long rest as often as we want, race is mostly a cosmetic choice.
Lack of darkvision should be affecting you in all of the underdark, shadow realm, and sewers in act 3.
Or alternatively you were using a light source, either option is fine. You get a ring that lights up targets, and theres several weapons with perma light on them, or you can cast the light cantrip on any weapon, but the range of the light is only about 6m so only works for melee and not ranged.
Now for a caster without darkvision, you are going to have a lot of disadvantage attacking from range, as well as with ranged weapons.
I use Lae'zel for most of the game too and she suffered a lot without either darkvision or a lit up weapon.
But technically no you don't need it as a racial as the spell for it lasts until long rest anyway and isn't concentration based, since I don't use gale much I use him to buff non elf party members with the spell.
