In my opinion, personas fail because it's literally profiling, which has limited use in identifying real world behavior. Who you "are" doesn't define what you

In my opinion, personas fail because it's literally profiling, which has limited use in identifying real world behavior. Who you "are" doesn't define what you do, so I think the activity model works better for UX work. Instead of maximizing a product for "Jim" from Marketing, optimize for what Jim needs to do and get done. Everything else is some sort of weird bias.