Processing times for I-130?

Hi, I joined the sub wanting to ask this because my dad is currently waiting for a response from USCIS for his case. His mom is currently a resident and soon to be citizen, and she petitioned for him but the first time it was denied, for both him and his brother. They re applied and his brothers case was sent to mount vernon and got a swift acceptance, but my dads case got sent to an agency in California, and it’s been like 3 years since his petition was sent, and it still shows up as “actively being reviewed”. Is this normal? What can we do? How long should he expect to wait? I believe he filed this in August of 2021. Any help would be appreciated, thanks.