Why is the transfer speed so slow from my laptop to mobile phone on wired cable?

I have a gaming laptop and a phone, both of which have USB 3.2 Gen 2 and Gen 1 ports. I also use a USB 4 Type-C cable. Now, recently, I have downloaded music files of over 300GB. If I transfer them one by one, it takes a lot of time. Today, I compressed the folder to a single zip file, and the transfer finished in less than 20m. Why is that so?