Vehicles aren't necessarily a necessity in PUBG, but they're crazy fun to drive and use in various combat situations.
This video highlights the craziness that occurs when cars are involved in any PUBG scenario, from combat to complete chicanery. Things are only made zanier due to some of the bugs present in the current builds of PUBG, meaning vehicles don't act exactly as they're supposed to. Explosions disintegrate steel and changes in elevation send chassis flying. At the end of the day, it adds levity to what is otherwise an often serious gameplay experience.