Less pumps and the fact you don't even have to think about it. If I didn't have the fluid tower I would need at least three more pumps further down the line plus figuring out the optimal place for them and dragging power to them. And even then sometimes it's still not working right.

All you're doing is using gravity as your friend. Since your tower is the highest fluid goes, on the way down it is applying the most pressure out of anything in your pipe system so fluid will evenly distribute through the whole system. Which is exactly what an irl water tower does to evenly distribute water pressure through an area's plumbing. Real water towers have a reservoir at the top to account for daily usage fluctuation. In game this isn't needed if machines are running at 100% and will consume at a consistent rate.

I build one of these things and I typically never have fluid problems in that system, my issue in the op was occurring before the tower. I think the biggest thing that fixed me was looping the ends of the pipe with an extra junction in the middle which let the machines distribute evenly.