Well, you can always type "select from some_table" and then move the cursor back after select and have auto completion. For example Jetbrains DataGrip supports this.
I get the sentiment, but personally I can easily imagine myself writing an autocompleter that would work fine with select before from. (I don't write much sql so I don't)
Just to clarify, my point is that when we do write sql most of us start by writing the from part, and even if we didn't I can just offer all columns from all tables I know about with some heuristic for their order when autocompleting in the select part.
