Slow drains can clear with strong clog removers like Insta-Flo with hot water to be applied at night so it can work on the clog undisturbed for at least 4-hours. It can damage seals of garbage disposals.
If you don’t have a disposal, you can use a caustic, powerful drain cleaner if there is some movement to the water. Often you need to plunge violently to create some passage for the water to drain through.
To use almost any drain cleaner start with small amounts first, chased immediately with 12 ounces of hot water (if allowed on the directions, if you are unsure use cold water) to push the drain cleaner out of the trap and into the drain line. Keep your face away from over the sink drain. Once that dose settles do it again, then another. The 3 doses should be covering the entire 6-foot line and begin dissolving the clog from the top down. Wait the maximum time and flush with hot water. Once the line appears to be clear, put the nasty caustic drain cleaner away and now treat for 3 or more days with the enzyme drain cleaner to finish the job.