Can there be damage to an iPhone 13 Pro Max from using a magnetic cable?

Solution 1:

If the cable is USB and Lightning standards compliant, there should not be a problem. You haven't included a vendor name, product name, or similar, so it's hard to say something specific about this cable - but it looks like it might be a cheap "China knockoff" and perhaps the vendor does not specify that it is compliant with those standards.

If you're asking in general whether having a small, relatively low-strength magnet located approx 1 cm away from the iPhone's charging port will cause problems - then no, that's very improbable.

There could be any number of other problems with the cable if it is not standards compliants (bad connections, improper shielding, low quality materials, etc) - but the simple fact that it includes a magnet does not itself constitute a major problem.