[rwmj]

That paper refers to interpreters in the traditional sense. However threaded code is not interpreted in the same way. After every instruction is a computed jump. There are benchmarks on this in the jonesforth code you can actually run and you will observe the exact problem there.

[cygx]

Note that the paper does compare a switch-based dispatcher to a computed-goto version ('jump threading') - cf figure 2. The latter used to have a significant performance advantage over the former, which is apparently no longer true (cf figure 3 (a)). That of course doesn't invalidate your point.