I think the tldr of their point is that Filippo thought a lot about cryptography but not about actual users or their requirements. What he thinks are cruft are actual features that users depend on
Also a solution that significantly reduces attack surface enough to motivate a migration from PGP in all the areas it is used, and a specific strategy to migrate everything to it.
Also form a standards team to maintain the spec to keep all implementations compatible so this work is useful long term.
If all of that happened I would seriously evaluate it and likely even help promote it. Few understand the shortcomings of PGP better than those of us that heavily rely on it!
Until then I suggest improving upon what already exists, or at the very least stop steering people away from the best effort solutions we have today and all the hard work from hundreds of people that go into maintaining them for free.