You realise that littering close orbit with more shit is just going to turn it into a whirling extraterrestrial claymore for anything trying to leave the planet.

Everything that goes up there should have a lifespan to come back down.

Yup, low earth orbit (LEO) still has some thin atmosphere that slows things down a tiny bit and makes them deorbit over time. That's why, for example, the ISS has to reboost to stay up and can chuck garbage bags overboard and not really worry about them. The deorbit time depends on a lot of factors including the mass and surface area. Starlink sats are supposed to passively deorbit in about 5 years.