We used to rent a car when we flew down. Not anymore. I think it was 9/10 years ago when we rented last.
Most of the time now we drive since we do split stays (add Vero, HH, etc.). We don't drive our car much while there. We don't mind using Disney transportation. We can count the times we use our car there.
We will go to Publix, sometimes
We will drive to another resort for dinner, sometimes
We will meet a local friend, sometimes
Reasons to have a car on-site.....(wether you traveled 5 years ago or yesterday

)
If you have small children, you might need diapers, formula, etc and really need to go shopping (but can always have items delivered)
Family of 3, 4 or more - might not pay to take Mears (maybe car service/Uber/rental?)
Most of your meals are offsite
You like the convenience of having your car and drive to all the parks, DS, Etc.
Like having the kids in the car seat
Meeting family/friends that are local or visiting Orlando and staying offsite
Our March trip - driving - WDW and Vero
October trip - flying - will most likely book Mears Shuttle/bus
I agree with a previous poster to write down what your plans are and see what might work best for you.