The Department of State uses priority dates to control the flow of immigrant visas as these visas become available. Your priority date is established when the I-140 visa petition filed for you is received by USCIS. Only a limited number of green card (immigrant visa) numbers are available each fiscal year (beginning October 1), and the Department of State adjusts the priority dates on a monthly basis to try to control the flow of cases to have just the right number (including family members) approved by September 30. These monthly adjustments can be monitored through the DOS VIsa Bulletin.
Over the past 15 years, there have generally been more immigrant visa applications by those born in the Philippines than there were visas available for people born in the Philippines, so long backlogs grew. At that time only those with I-140s that had been filed long before became eligible to get past the NVC (National Visa Center) stage and obtain an immigrant visa at the US consulate. However, in the past couple of years, the number of visa applicants decreased so the backlogs declined, and most applicants in your category (EB3 Philippines) were able to go through NVC to the consulate stage with much shorter delays.
Then last year, as the priority-date backlogs shortened and even disappeared, COVID-19, hit reducing consulate staffs and the President banned immigrant visas for most applicants, so consulates around the world reduced the issuance of immigrant visas to a tiny fraction of the number normally approved and huge new backlogs grew, even though technically all priority dates were “current”. A lucky few were able to obtain visas based on health-care waiver requests, but those requests were often denied. Right now EB3 Philippines priority dates are all “current”, and we hope they will remain so for a long time. KHR made over 80 such waiver requests for nurses, but the vast majority were either denied or simply never acted upon. Now that President Biden has lifted the immigrant visa ban, we should see a general acceleration in visa interviews, but unfortunately, healthcare workers (nurses) will no longer have priority over other applicants.
DOS says they expect to increase the flow of immigrant visa interviews, and we have recently witnessed a marked increase in scheduled interview appointments, but the backlogs are still substantial (the current backlog at the US consulate is about 6 times as large as their “normal” backlog).