LG has had the following GH24.... models:
SH-222AB (temporarily returned to 22x models)
SH-224BB (...Back to 24x models)
Compare to, from LiteOn,
Every time a new, more cost-effective chipset or OPU or something similar comes out (or when a component is discontinued), a new drive model appears so the manufacturers spend as little as possible. It happened across manufacturers who used MediaTek chipsets. If we include 22x models from before each of the above made a 24x drive, the list grows due to similar revisions.
Of the other manufacturers which put out 24x models:
Optiarc only did an 18x, (rebadged a 20x), a 20x, (rebadged a 22x), and three 24x models.
Pioneer did an 18x and a few 20x models (and rebadged a few faster models).
Everything else is a rebadge of one of the above, more or less. So for those high-volume producers, it was sort of necessary to save every cent to keep business. And LiteOn reused leftover bits from Optiarc for a couple of models, except for the x24 Y which was a clone of the genuine Optiarc 7240. But you can imagine that was to keep up with perceived demand.