It's entirely up to you, like @Tphauser said, some owners like it because they get a chance to meet the potential renter first before committing to the reservation. You can definitely say no too.
We get this request too from time to time, and I just politely explain that renting our RV is something I do on the side (in addition to a full time job), and I don't have the spare time to set up separate tours in addition to all the work that goes into prep between rentals. I do offer the option of a video tour (using facetime or zoom) where I walk through and show them what they need virtually, and that is generally good enough for most renters.
On a somewhat related note, if you are uncomfortable with having renters come to your house, you might consider using a nearby public area (park, mall parking lot, etc...) to do your pickup/dropoff instead. We use a school parking lot that is close by, and I put the school's address into Outdoorsy for the RV's location. This way renters never actually get our home address, which gives us a bit more peace of mind if we ever have an issue with someone. This would also give you a place to meet potential renters if you did ever want to offer tours before confirming a booking.