When the pandemic hit, rental companies sold their car fleets as no one was traveling. Then semiconductor shortage created a shortage of new cars. With insufficient cars available, rental prices skyrocketed to hundreds of dollars per day in popular destinations (up from $20-$35/day pre-pandemic).
Lack of rental cars limits travel options – many destinations do not have public transportation alternatives.
One suggestion is to use an AirBnB equivalent for cars – where people rent out their own cars.
Source: Car rental shortage trends: here are alternatives for holiday travel