#3000 in all books on Amazon is pretty awesome. Ignoring 5E as an outlier which distorts perception, it's a very successful book.
That depends on what their expectations were prior to release. You appear to be comparing it to all other non-WOTC RPGs to determine if it's doing well, but that's not necessarily an accurate perception either.
If they printed sufficient quantities and hired staff with 5000 rank or worse in mind for this point in the sales trend, then it's awesome. Like the Jordan Peele movie Get Out, which cost $4.5M to make and had low expectations and made just over $250M in box office (which was lower than a Marvel movie that year by vastly exceeding its costs).
If however they printed sufficient quantities and hired staff with 500 rank in mind or better at this point, it's an awful failure. Like the movie Waterworld, which also made just over $250M in Box Office and that deceptively looked good relative to other movies out that year, but cost more than the studio received from box office sales to make it, resulting in failure.
And we just don't know what their expectations were prior to release, and we won't likely ever know (because Paizo has always said, even days before failure of their digital gaming product, that everything was always going fine and exceeding expectations).
The only one thing I can think of which we could figure out is what the sales rank of the books were in the 6 months prior to the announcement there would be a 2e. Because we can be pretty certain their expectations are that 2e needed to sell better than 1e was selling at the tail end of that edition. If it's selling worse than 1e was already selling, then it's bad. I don't think we have that data handy but I strongly suspect it's selling better than 1e was selling, at least for the moment.