Why does USCIS constantly change their timelines and cause delays?

USCIS’s timelines are constantly changing and foreign nationals across the board are seeing processing delays for various reasons. One of those reasons has been the sweeping changes as well as technical adjustments by the Trump Administration since 2017. The other has been the COVID19 pandemic which has crippled USCIS operations. The Trump Administration instituted more than 400 executive actions that affected visa processing and vetting.

Under the Trump administration, I-140 and I-485 applications were halted and delayed because USCIS was directed to add additional vetting and other policies which significantly slowed processing. Leadership at both USCIS and the State Department encouraged adjudicating officers to issue blanket denials of cases, issue more requests for evidence, and to generally slow the immigration process. Other policies under the Trump administration included requiring repeated biometrics of children and spouses, requiring in-person interviews, and rejecting various applications contrary to regulations. COVID19 also impacted USCIS has they had to close their offices and work from home which led to inefficiencies and other issues.
The Biden Administration has vowed to undo many of these policy changes but such action will take a significant amount of time. Rules require time to undo given the legal and constitutional constraints required by law. Therefore, USCIS’s timelines will likely continue fluctuating.

Do These Same Issues Effect the Department of Labor (DOL)?

The same issues in terms of processing times posted on the DOL website are the same as the USCIS website in terms of accuracy. Applicants can generally access processing times for DOL here. When accessing the link, the Department of Labor has a section titled “PERM PROCESSING TIMES”. This section is updated at random by the Department of Labor.
The date that the chart was last updated is presented beside the title of the section. Within this section, there is a chart that presents the current processing queue. It presents which cases are under Analyst Review, which shows which cases are under initial review by the Department of Labor. It presents which cases are under Audit Review, which presents cases that were audited at the date displayed. Lastly, it presents which cases are being reviewed that are Reconsideration Request to the CO.

Despite the information presented on this website, the dates reflected are not necessarily accurate. The dates are inaccurate at times because officers move at different speeds and are not legally obligated to follow the timelines that are outlined on the websites. The dates listed on the Department of Labor's website should be used as a mere guideline due to this discrepancy.
Finally, it’s important to note that the DOL process is an entirely employer-driven process. They are the ones that complete and file the labor certifications.