Please tell me this isn't a major plumbing issue

My house is about 60 years old. One previous owner/tenant for the 60 years, then was vacant while it was “flipped” and I purchased it 2 years ago.
We are on a septic system that was checked and certified when we moved in.
About a year ago I had a plumber come in and snake...
Please tell me this isn't a major plumbing issue