I've bought cheap calipers from a discounter, and they're accurate to ~0.01 mm when compared to expected sizes of e.g. coins or measurements taken with a fancy

I've bought cheap calipers from a discounter, and they're accurate to ~0.01 mm when compared to expected sizes of e.g. coins or measurements taken with a fancy caliper set I had access to. I'm sure there are some downsides that would show with regular use, but for my hobbyist use case (occasionally take measurements, typically only needing to be accurate to something like 0.1 mm), they're more than enough. I've had one case where I needed sub-0.1mm accuracy and they also did that job perfectly. Absolute scale would be a valuable time-saver though if I was using them professionally, and machinists probably benefit a lot from having coolant-proof versions.