Faerie Fire provides advantage to all combat rolls for the entire party. This is far too powerful for a first level spell, and very imbalancing. Why should an attacker get advantage simply because the defender is glowing? It shouldn't make the hit significantly easier.
IMO, this is an oversimplification. Faerie Fire does not provide advantage to all combat rolls for the entire party.
Faerie Fire provides advantage to all combat rolls for the entire party against any creatures that were inside it's 20 foot cube and failed their saving throws against it, so long as the caster is able to maintain concentration. That's quite different.
While it can certainly be a worthwhile spell, one needs to consider that unlike many (non-cantrip) spells, it does absolutely nothing on a successful save. Since it requires concentration, it not only prevents you from casting many other spells that are as or more useful (Entangle, Spike Stones, etc) but it can also be brought down by simply damaging the caster.
In the Underdark campaign I'm currently playing we currently have two drow warriors in the party. While their Faerie Fire has proven useful on occasion, there have been quite a few times when the targets all made their saving throw, making it a wasted turn. Even when they do successfully land the spell, it often makes the drow who cast it a priority target.
In a campaign previous to that one there was a Circle of the Land Druid who cast it a few times and found it quite underwhelming compared to his other options.
As such I haven't found it to be a problem, IME of course.