Rubber hose from brake fluid reservoir, 1992

[c4koh]

Hi,

I posted last week re: some corroded (but still intact) steel brake lines. I also see the braided stainless steel flex, which is in good condition.

While looking into my brakes more, I also saw that there's a rubber hose coming out of the brake fluid reservoir, and it leads down to a flared steel line under mid-driver-side, along with a cluster of some other steel lines.

What is this doing? I don't like simple rubber hoses with hydraulic fluid going through - presume it's not doing any work?? Anyone replaced this with a steel line?

Thanks

Steve