According to European consumer protection laws (and those of some US States), you are the owner of your data and you can request an export of the data from flightmemory. The first reaction is usually to send you a PDF, but you can insist. Then they usually send you some rotten excel-sheet with poorly formatted columns. When you insist a third time (and potentially threaten them with consumer protection laws), they will send you a nice excel-sheet with data. But it is a hassle.

Flightmemory is a clear example of network effects and monopolistic behaviour, and they know it. Then, they could, with just a few hours of programming investment, probably revamp the site and create a tool which actually works on a mobile phone and has a design which is more like 2023 and less like 2003...