Low shank foot fitting has been around since time immemorial, i.e., pretty much from the beginning. However, for some reason the foot height was raised by 1mm some time around 1920, and after that everyone followed that new standard.
If you try to use a modern foot on an antique machine, thinking low shank is low shank, you’ll find the pressure on your fabric being so high, it will be puckered and ripped; if you try an antique foot in a younger machine, it may not even be able to form stitches due to insufficient pressure.
An antique foot on a modern machine does not touch the ground, and yes, it is supposed to.
So if you want to use your extensive collection of low shank feet and attachments with your favourite Victorian darling, you need to raise her presser bar by 1mm. You will no longer be able to use her original feet, but hey – that’s a choice you make.
Raising the bar is not that hard, please see my post on changing foot fitting by replacing the presser bar. You don’t need to replace yours, just raise it, the pressure adjuster will still work just fine because the difference is small.