Brake fluid is hygroscopic and will accumulate water over time despite being in a nominally sealed system. Water in solution with brake fluid noticeably lowers the boiling point which leads to issues under repeated braking (e.g. down long steep hills) as the fluid boiling means you lose braking capacity in that circuit.

You should ideally be changing the brake fluid every few years (2-3 being the typical recommendation) and that applies even if the brakes are used less often.

Electric cars do have oil that will ultimately need changing but it’s less exposed to contaminants than the engine oil in a internal combustion engine and therefore will last a lot longer. EVs typically have a reduction gearbox and differential and these will require oil changes in a similar fashion to a manual gearbox or differential in a ICE vehicle - i.e. barring exceptional circumstances it will last long enough to get out of warranty but don’t believe it will never need changing.