A hot shoe cover can offer a little protection, mainly by covering the contacts from dust, moisture, and minor knocks, and by smoothing over the sharp rails so they’re less likely to snag on clothing. But in normal use, an uncovered hot shoe is usually not fragile, and many photographers never use a cover without problems.

So for most people, a hot shoe cover is optional rather than essential. It may make more sense if you rarely mount a flash or accessory and want basic protection while the shoe sits unused. If you frequently attach flashes, triggers, or microphones, the cover is mostly a nuisance.

There are also possible downsides: on some cameras, a cover can be detected like an attached flash and may prevent the built-in flash from popping up. And if a cover presses on contacts or springs for long periods, it could theoretically contribute to wear rather than prevent it.

Bottom line: useful as minor protection and convenience in some cases, but not something most photographers need to worry about.