Subletting a leased or rented vehicle

Car rental companies have different profiles and different target customer groups (e.g., replacement car rental companies, long-term rental companies, premium car rental companies). In any case, the fundamental challenge for a newly established company is to acquire a fleet of rental vehicles. The simplest solution is to purchase vehicles, but this requires having sufficient capital or taking a loan. Therefore, a good solution is a lease agreement or a vehicle rental agreement – they allow the rental company to spread the cost of obtaining a car over time. But in each case, is the possibility of profitably providing customers with owned vehicles unlimited?