It seems like a good idea... until the first terrorist leaves their suitcase bomb in Manhattan, mobster uses this to arrange drug mules or child trafficking, or shady business or their employees goes through bags looking for valuables.

Most people can simply mail their luggage to their hotel. Only a limited subset of travelers who use Airbnb or are homeless would need this service.

It seems like a better business model would be somewhere at the airport where you can pay someone to watch your luggage if you want to explore / go to dinner / etc. and know you're going to get everything back (like some sort of branded plastic-wrap "seal" with writing on it). Fewer locations needed and infinitely more customers. Of course, the downside is there's nothing to patent or can be protected in either business, it can be knocked-off ad infinitum.