What are you trying to backup to? I’m assuming some 3rd party service? You might have to break it up by year or something and do it in batches.

Apple M1 Max, Ventura 13.4.1 (22F82), Safari Version 16.5.1 (18615.2.9.11.7).

My guess is this is the service that has the backlink feature in the top left near the time. So when you open an app, you can easily go back to the previous app.

But, it seems like a bug in iOS that this shows up in your screen time.