Hydro jetting uses high-pressure water to clear grease, roots, scale, and debris from sewer and drain lines. It is one of the most effective cleaning methods available, but pressure that clears a sound pipe can worsen damage in a compromised one.
The question is not whether your pipes are old. Plenty of older lines handle jetting without issue. The question is what material your pipe is made of, what condition it is in, and whether anyone has looked inside it before recommending high-pressure cleaning.
This article breaks down the risk by pipe material, explains what makes a line safe or unsafe for jetting, and covers how a sewer camera inspection changes the decision.