A big shout out for plumbing video inspections. I wish I had done it when we bought our four bedroom home in Livingston, NJ in 2018. After several slow drains and backups I finally popped ($400) for a sewer line camera inspection. The results were a we have a copper sewer main pipe (street to house - luckily PVC in the house) from probably when the house was built in the 1960's and will need to pay $5,800 to replace it with PVC which our insurance company may or may not cover. But at least it's better then a sewage backup in the middle of the coming Covid winter.
Lesson 1 learned, it's worth it to pay for extra's outside the basic home inspection. Lesson 2 leaned, if the house has a tree in the front of it and is older it may have copper pipes with tree roots feeding on them and be closer to a complete blockage then you realize. Another warning sign you'll soon have sewer problems is if the toilet water levels change for no reason.