If the vaccines work to “prevent death,” one might have reasonably expected to see COVID deaths decreasing, compared to this time last year, when no one had been vaccinated. But, for whatever reason, that isn't what the data show.
You make a good observation. The only thing that I would add is that the data in this state is hopelessly skewed and not reliable in any normal sense of the word. One would think that the inconsistency that you have noted would cause them to skew in a different direction, but their only hope for the next election is to keep the panic going.
I should note that the COVID death data I'm citing here is that which is reported to the National Center for Health Statistics and reported out by the CDC. A "death involving COVID" for these purposes is defined as "Deaths with confirmed or presumed COVID-19, coded to ICD–10 code U07.1."
What this entails is that, whatever an individual doctor or hospital in a given state put down on an official death certificate as a deceased's cause of death gets reported to the NCHS. It isn't a call made by either the NCHS or the CDC. The validity of the "cause of death" determination is only as good as the particular doctor or hospital, in a given state, makes it.
Thing is, unless the basis for those cause of death determinations in Washington has changed from 2020 to 2021, such that every doctor and hospital has embraced such a change, we still have the apparent anomaly where COVID deaths have increased (and increased considerably) in Washington starting in August 2021. Otherwise, whatever a "death involving COVID" happened to be in the state of Washington back in 2020 remained a "death involving COVID" in 2021 ... and starting in August 2021, there have been more of them compared to the same time period during the prior year (i.e., pre-vaccine).
And while I certainly appreciate that there are entities out there that want to be keep the fear factor high, I am unaware of any governmental entity (be it the CDC or any state agency) that is willing to assert that the much-touted vaccines no longer work to "prevent death." To the contrary, I haven't see it reported anywhere that COVID deaths are up in the U.S. in 2021, compared to the same time period in 2020. To the contrary, crickets.