i dont know about 25GB file transfers but
i routinely copy 1or2 meg PDF files between my iPhone and a NAS box using my home network wifi. Just takes a second. No extra cables or anything. The iPhone mounts the NAS box really fast.
The iPhone Files app works ok. I actually like it.
No reason to suspect larger files couldn't be accessed.
I am sure the same iPhone could directly access say a MBP on the home network, again no special cables.
I have a really old wifi box but just over ethernet cable between say 2 iMac's transferring 25G would take a few minutes.
Try transfer video file(s) recorded by your iPhone for as big as your iphone storage allows. You’ll see the reliability, stability and transfer speed are not the same as you would expect from other computers / devices, wired or wireless.
The Files app even would crashes a lot when I move large files and folders between split view windows. But of course 1 or 2 MB files wouldn’t be a problem.
I also experienced transferring a 300MB audio file (.wav) from an SD card to the iPad via card reader dongle using the Files app. It transferred okay pretty quick, but the file is corrupted with audio noises. Many people experienced this with video, image and other files as well.
And the problem is not only the Files app alone, it’s the whole iOS / iPadOS writing controller that being a bottle neck in large file transfers speed. It’s being discussed in many forums.