Why does U-boot support FS?

The purpose of U-boot is only to start the kernel image, and the image itself does not need the concept of FS. Why does it support FS in U-boot?
I have discussed it with Fred. My personal summary is as follows:
Benefits:
> You do not need to specify the start address and maximum length of the kernel image stored in flash;
> If the new kernel image is compiled, replace the existing image directly, and you do not need to re-write it under U-boot;
Disadvantages:
> Increase the size of the U-boot image;
> The kernel image is still visible after Linux is started, which may cause damage;