As a separate plumber, I would remove the p-trap and snake it until I can get good flow, then install new p-trap.

From my experience plumbing and replacing drain lines, it’s the pipe from the kitchen to the main that backs up and clogs first. A kitchen drain will be 1 1/2” or 2” pipe, and a main will be 3”-4”. Problems come up when the drain isn’t supported properly, or the piping has a lot of warp with low and high spots. As it fills with grease it will begin to sag more in spots and exasperates any existing dips.

I recommend people use enzymatic drain cleaners, not acid cleaners, once or twice a year with hot water to break down any grease deposits.