Those things were built like tanks. As long as the main inner rod (name is escaping me right now) isn’t literally bent, and you can keep uo with maintenance/minor repairs it’ll probably keep running forever.

I’m a bit of a collector of old sewing machines; I love how simple a machine they are and yet so incredibly useful! They were also built to be able to be repaired by just about anyone, which is so cool. If you had to pick a single machine that shows how much capitalism has engineered backwards into built-in obsolescence from something we had already figured out, the sewing machine would be a good example.