What key long-term advantage do ground-based telescopes possess over space telescopes positioned at locations like L2?

Answer

The ability to be repaired, upgraded, or refurbished.

Hardware on Earth can be physically accessed for maintenance, repair, or technological upgrades over its operational lifetime, which is impossible for instruments fixed in deep space.

What key long-term advantage do ground-based telescopes possess over space telescopes positioned at locations like L2?
telescopelimitgroundobservationatmosphere