I have mine for when I need it, not for everyone else’s convenience. I’d be worried about what shape it would come back in every time I rented it out. You’d want to make sure to carve things out of the contract such as a wheel bearing failure otherwise you could be liable for fixing the wheel bearing, getting a different trailer for them to use, etc.
I borrowed mine to a coworker one time and it took him two weeks to get it back to me since he was too lazy to finish unloading it. Drove me nuts as we were getting ready to move to a new job site later that month.
Many people treat other people’s stuff like trash. If you’re not one of my few close friends I’m not borrowing my stuff or trailer to you. I don’t know if the amount of money you’d make back would be worth hassle it could be.