Should I buy a roto-molded cooler or is injection-molded fine for most people?

Roto-molded coolers keep ice frozen for days and are tough enough for off-grid camping, but they cost $300+ and weigh forty pounds empty. Injection-molded coolers are cheaper, lighter, and fine for a picnic or day at the beach. For most people, injection-molded is totally adequate — most overestimate how much ice retention they actually need.