Well, the stuff is there right now, but there’s nobody harvesting them because it’s nowhere
near economically viable. Maybe someday in the future, but we can’t just keep polluting the orbits while waiting for that hypothetical day.
LEO stuff is going to deorbit due to drag anyway sooner or later, and we very much would like that to be ”sooner”. Higher orbits are stable for a long time, and intentional deorbiting is not feasible anyway due to the amount of delta-v needed. So there are ”graveyard orbits” into which satellites should be moved before they’re out of propellant.
Anyway, intercepting and capturing defunct satellites on a large scale would be surprisingly costly because of the large variety of orbital planes involved. Inclination changes are expensive with regard to delta-v!