That's an excellent and very practical question. As someone who's helped both my young kids and my parents with everyday tasks, I've thought about this a lot. The short answer is: it completely depends on the design of the specific trash can.
Many modern outdoor bins, especially those in public parks or newer residential complexes, are designed with accessibility in mind. You'll often find models with pedal-operated lids. These can be great for elderly individuals who might find bending over or gripping a handle difficult, as they simply step on a lever. For children, these pedals might require a bit more body weight to engage, but many school-aged kids manage just fine.
However, the classic swing-top or lift-up lids can be a challenge. They often require a firm grip and a pulling or pushing motion that can be tough for small hands or arthritic fingers. Heavy, spring-loaded lids meant to deter animals are particularly difficult. I've seen my dad struggle with a stiff lid, and my youngest needed two hands and all her strength to open one at the playground.
Safety is another layer. Easy-to-open lids are accessible, but you also don't want a lid so loose that it could slam shut on little fingers. The ideal design finds a balance—enough resistance for safety and animal resistance, but with a mechanism (like a large, easy-press pedal or a wide, ergonomic handle) that minimizes strain.
So, when choosing a bin, look for features like large pedals, smooth-spring mechanisms, or handles with good leverage. If you're concerned, test it out! The right bin can make taking out the trash simple and safe for every member of the family.