Transferring data from old iphone to new iphone with phones adjacent is a clear mess. Trying from past 24 hrs and always at the end it says unable to do data transfer

I did recently upgrade to new iphone 15 and the data transfer by keeping the two iphones adjacent to each other is a mess. Its been 24 hrs and at the end ~ after 20 min , it says unable to do data transfer and to start the process again. The process starts from setting up face id to again complete transfer.

I am transferring data between iphone13 pro max to iphone 15 pro max.