iPhone hotspot use

That depends. Using the hotspot versus having the phone in sleep or off will cause it to age more quickly but, that would apply to using the phone for anything. Using the phone's hotspot versus using the phone to play games, no, that won't make a difference.

If you have the option, plug the phone in while you're using it as a hotspot, especially for extended periods of time. That will decrease wear and tear on the battery.

You can use the hotspot function without any issues.