Isn't that the same thing? Having an adjustable fee even within a ranging system of 1,2,5,10...300 sat/vbyte. What other customisation can one need than that.
Full fee customization means that I can pick any number I want, not the ones the software specifies. If it goes 1, 2, 5..., where is the 3 and 4? Not only that, but maybe I would like to pay 5.5 sat/vByte and not 5 or 6. Electrum mobile doesn't allow me to do that. It's not that important if you are sending a transaction and paying 70 or 70.5 sat/vByte. But back when the fees were low, there was a big difference between 1 and 2 sat/vByte. Even a 1.5 sat/vByte is 50% more expensive than a transaction paying only 1 sat/vByte. On Electrum's desktop version, I could pay 1.1 sat/vByte and have priority over anyone paying only 1 sat, but still save money compared to what I would have spent if I paid 2 sat/vByte.
Consolidating inputs can also help to lower the fees. It is always a good idea to regularly consolidate our inputs unless it is a cold wallet. CMIIW.
Consolidating is OK when the network conditions allow it. It gets quite expensive in situations like what we have witnessed with the Ordinals.