Sure that part is a specific problem which is that new browsers basically want to declare their hacks profile against people who have already written sites and won't update them.
In practice when you make your new set of hacks the string you can always evaluate whatever cruft in the useragent today, but next browser shows up.
It does make the user agents insane but I don't know if there's any obviously better system for the problem, even with hindsight
In practice when you make your new set of hacks the string you can always evaluate whatever cruft in the useragent today, but next browser shows up.
It does make the user agents insane but I don't know if there's any obviously better system for the problem, even with hindsight