This applies to nearly all insects too. When an insect is unable to molt any more, then it usually means it’ll die soon since they can only really regenerate their organs when they molt. It’s why arachnids and crustaceans can live so much longer than most insects, because they can keep molting and hence rejuvenate themselves.

When insects injure their exoskeleton, the most they can do is exude a patchwork fix. When spiders and crustaceans lose an entire leg, they can regenerate it after a molt or two. The most primitive insects like silverfish have no metamorphosis and can keep molting as well.

It’s telling that the longest lived insects, termite queens, are protected by an entire colony and do not need to move around, minimizing the damage they sustain.