I really hate the Disney buses and used to rent a car for every trip, but they have gotten pretty expensive since the pandemic. Although it's convenient to hop in my car to go to the parks or dining at other resorts, I also am not a fan of drinking adult beverages and driving- especially not driving a rental car! Now we take Mears bus to our resort and back to the airport. It might take a little time, but it's so much more affordable! I also don't have to worry about filling a gas tank before returning the car. ['Horror' story from a friend; she filled up at Disney Springs the night before returning her rental, but didn't top up the tank enough- she had to pay something stupid, like $29, for gas when she returned the car as Dollar said the tank wasn't full.] We get a grocery delivery from Kroger so I don't need to uber to a store (and waste my vacation time AND money, hahaha). If we aren't planning to go offsite (like to KSC, or to visit friends in the area), I don't get the car.
If you do want to rent a car, check out carrentalsavers.com. Lately they've had the best prices, IMO. I avoid renting from Dollar like the plague; they have tried the car insurance "bait and switch" thing, insisting that I have to buy their insurance (not true, according to the FL attorney general). If you rent a car and don't already have an EZPass, use the Visitor Toll Pass. The 'kiosks' (actually more like vending machines) are right there by the car rental places in the terminals. Also, when returning the car, there is a gas station at the south exit of the airport. They aren't the cheapest, but they aren't the most expensive, and they are right there at the airport so easy, hard to get lost.
Honestly? I never thought I'd say it, but renting a car just isn't cost-effective anymore when there are only one or two of us traveling. I find as I get older, I worry more about the hassle of renting (filling the gas tank when returning, getting there on time, being charged for parking lot dings or whatever) than it's worth for the convenience.