I want to like BPF, but so few of my problems are in the kernel. Performance problems are usually at the application layer, either in my code or my dependencies. Even in the rare case that it something outside of my control (like the compiler, or the nature of the data), it's almost never the kernel. Lastly, when it is the kernel's fault, there's usually a sysctl or other knob to turn to fix it. Real kernel problems, such as some missing functionality, are usually better resolved by committing changes to the kernel itself, not so much on demand filters. BPF is a solution in search of problems.