Tedium
Hypothesis: all other things being equal, if an activity is tedious, it is wasteful. If it is wasteful, you shouldn’t do it.
This can be articulated as the Jolly Contrarian’s third law of worker entropy:
There is a 100% correlation between (i) activities that, however important they might seem, in fact have no value, and (ii) activities which are tedious.
If an activity is 25% tedious it is 25% wasteful.
Tedium and interest
I can’t prove this, but tedium is not the opposite of interesting. There is an intermediate purgatorial state which is not particularly interesting in any meaningful sense of the word, but is not tedious either. Bruce Springsteen’s album Nebraska, for example.