Desktops shouldn't really be a problem as cases/towers are usually good at protecting the internal components from electrostatic discharge although, as mentioned by AdrianG001, you should take care to clean your hardware on occasion to prevent any buildup such as dust (can potentially be very bad for internal devices such as graphics cards or even the motherboard).
I think laptop computers are a different story though, as the design is more compact with a much thinner layer of protection and less separation in distance between components, leaving them more prone to ESD. In this scenario, as long as there's no way to generate static electricity from the floor (often an issue with carpets), then I believe it should be fine.