There’s no BIFL cordless vacuum because of battery drain and since they’re designed to be lighter.

The best course of action is to buy the best value that meets your criteria. Dyson’s are popular which makes getting additional batteries easier, however, be careful with quality. A battery lasts 1.5 to 2 years IME.

The V8 and LG A…9? Vacuums represent the best value I’ve seen, but lately the V8 has been near the price of the V10 or V11. I’d just recommend trying to keep things as close to $250 as possible and expect to buy (or swap parts) every few years. Totally worth it for the convenience.