The Mass Effect trilogy includes a variety of species to populate the Milky Way Galaxy, and each has its own history, culture, and defining features. While there’s a lot to explore when it comes to the races of the Milky Way, details that pop up early in the trilogy can lead to questions that are answered later or perhaps only answered through digging into extra information provided either in the game or through additional content. Questions like why Tali and the rest of the Quarians wear special suits are luckily answered through completing quests.

https://screenrant.com/mass-effect-tali-visor-off-quarian-immune-system-op-ed/