It doesn’t seem like trivialism is useful at all, but usefulness is not correlated to truth according to the priors of proponents of trivialism (or at least, I expect that to be true).
It isn’t practically useful, no. But from a politico-philosophical standpoint, if dialetheism can’t distinguish itself from trivialism, nobody will bother to study it.
By analogy, a running joke in some mathematics circles involves people studying Hoelder continuous functions with parameter greater than one. As it turns out, all such functions are constant. However, before one knows that fact, there is a very nice research program that can be run proving all sorts of interesting properties of such functions, e.g., they are all smooth (which would be unexpected to such a mathematician, as when the parameter is one they are not even differentiable everywhere). Such a research program is ultimately useless, but only after one knows the critical fact.
As for the overwhelming amount of empirical evidence against trivialism, this is covered in the dissertation. However, a shorter argument one could give is that humanity will likely only ever “observe” the truth value of finitely many propositions. That subset is of measure zero in the set of all propositions, i.e., practically no evidence. Since trivialism necessarily rejects the law of non-contradiction, observing finitely many false sentences does not imply that all sentences are not true. For example, perhaps it’s just much harder to “observe” that the sentences we’ve observed to be false are also true, as would be the case if, say, proving their truth required a proof of length 3^^^3.
It isn’t practically useful, no. But from a politico-philosophical standpoint, if dialetheism can’t distinguish itself from trivialism, nobody will bother to study it.
By analogy, a running joke in some mathematics circles involves people studying Hoelder continuous functions with parameter greater than one. As it turns out, all such functions are constant. However, before one knows that fact, there is a very nice research program that can be run proving all sorts of interesting properties of such functions, e.g., they are all smooth (which would be unexpected to such a mathematician, as when the parameter is one they are not even differentiable everywhere). Such a research program is ultimately useless, but only after one knows the critical fact.
As for the overwhelming amount of empirical evidence against trivialism, this is covered in the dissertation. However, a shorter argument one could give is that humanity will likely only ever “observe” the truth value of finitely many propositions. That subset is of measure zero in the set of all propositions, i.e., practically no evidence. Since trivialism necessarily rejects the law of non-contradiction, observing finitely many false sentences does not imply that all sentences are not true. For example, perhaps it’s just much harder to “observe” that the sentences we’ve observed to be false are also true, as would be the case if, say, proving their truth required a proof of length 3^^^3.