Are there any more efficient generalized solutions to doing this?
Append Fields : this is the method I would typically use, but say your list has 100,000 ranges in it. Do you really want to cartesian product 100,000x your rows?
Generate Rows : say the ranges are 1,000,000 numbers wide. And your values could be 10 digit decimals - you don't want to have to generate a row for every possible number between 0 and 1,000,000 in order to then do a simple join.
Formula Tool : on its own this doesn't seem generalizable, you have to code the formula and each range by hand. So if you have 1000 ranges, you'll be typing for awhile.
Tile Tool : you have to know and type in each range bound, so again it's manual and if you have 100,000 ranges in it you're going to have a bad time. It doesn't seem that you can dynamically tile based on another value
Let's say you have a list of 10 million customers, and you want to assign some value based on their income. But you have 10,000 potential ranges you want to assign, and they aren't all equal (i.e. not all 1000 dollars apart). What would you do to have a clean, fast, efficient workflow?