[NoiseBert69]

There are thousands of weather balloon starts every day without any damages to airplanes.

It's not factor as long they are not crossing a specific size/weight - jet engines and windows from airplanes are tested to withstand a direct impact.

[m4rtink]

Yeah, and pico baloons are extremely tiny, often at 10 grams or less, comprising some very thin plastic, some thin wire and tiny PCBs - this is also how they can fly so high for so long.

Lost of types of hail will be much heavier and harder on impact for example.