It depends on how straight your finger is. Mine's pretty straight. I've done lots of scale work and find that using my finger for leveling is capable of dosing consistency equal to a straightedge.

One advantages of your finger is it's almost always handy... Sorry If you are making drinks it should be clean already. Plus you can easily updose or downdose to varying degrees using the same tool. Also, its rounded edges are less likely to drag ridges into the top, which I've observed with some items (like the doser lid). Plus its free .

Other tools are great. I use my finger. Whatever works for you.

There are several WBC competitors skipping both the distribution and leveling. It could work with a VERY precise grinder and eye and control to get it even, but yes, it's possible. I have crooked fingers (arthritis or whatever its called in english) and level with the back of my hand. Took a bit of practice to achieve a consistent result (ie. using the same spot each time as it is slightly curved) but level is the same each time.

Another simple, fast and reliable method is stirring the grind with a needle. I use a long, 0.8 mm needle with a slighty blunted tip. Dosing, stirring, tamping. Works fine for me.