Light blocks are very cool and not game-breaking for survival, so there should be a way to get them.
Glow squids are a somewhat interesting mob that is almost entirely useless. By requiring 81 glow ink sacs for a full light block, this adds a reason to desire them.
Other light block data packs made it too simple to acquire loads of them, in my opinion. The higher cost in this datapack makes them rarer rather than becoming a complete replacement for any other source of light, while also having a simple recipe that feels like vanilla.
You can craft strength 11, 12, 13, 14, and 15 light blocks out of other (2, 4, 6, 8, 9) light blocks and you can use a stonecutter to obtain weaker-than-10 variants. This works around a limitation in datapacks where recipe ingredients can't require specific block states.
