That's an excellent and increasingly common question! The short answer is: technically yes, but practically it's complicated. Many biodegradable or compostable bags *can* be manufactured to fit standard urban bins. The core issue isn't the bag itself, but the mismatched lifecycle between the liner and the waste system.
Most city waste is sent to landfills, which are designed to *prevent* decomposition (to avoid methane leaks and groundwater contamination). A biodegradable bag in an airtight landfill will not break down any faster than a plastic one. For it to work, the bag and its contents need to reach an industrial composting facility—a service most municipalities don't offer for public litter.
There are also durability concerns. Public liners face sharp objects, heavy loads, and weather. Some compostable films can tear more easily than conventional plastic, leading to messy bin contamination. Cost is another factor; these specialty liners are often more expensive for city budgets.
So, is it pointless? Not entirely. Forward-thinking cities are piloting programs in controlled areas like parks with food-only waste bins, where the bag and contents can be collectively composted. The real solution is a system-wide approach: matching the bag material to the destination of the waste. Until then, the most impactful step for cities is often reducing liner use through public education and well-designed bins that stay cleaner. The ideal isn't just a "better" bag, but a smarter, integrated waste system.