One time foundation fix or forever money pit?

[Mitchell Learmonth]

Bought my first house hack (duplex) in Dallas TX last December. Sloping floors lead me to get an Engineering report; they recommended 6 exterior pilings, sistering 169ft LF of 2x6, and 24 LF of sill plate. Also found out 16 pilings were installed less than a year ago by the previous owner. The property has poor drainage and seems like a it could’ve been the cause (working on fixing that now). 

Are all foundation problems fixable? Or is this damage unusually severe and I should expect to be repairing pilings every year or so? 

Any advice would be greatly appreciated, thanks y’all! 

-Mitchell