New 110 Skilling content confusion

Hello, fellow Scapers how are we all doing?

So Jaqex has just announced a new upcoming 110 skilling for certain skills 1st one being mining and smithing enjoying the content but it's left me with some confusion that needs to be addressed that Jaqex hasn't answered anywhere that I can find

Back in the old days, we had enough content to proceed from 1-99 in most skills over Runescape's long history a large majority of the player base has gained 99s in a lot of skills so they have finally proceeded to now slowly bring some skilling content up to 110 after asking for a very long time

My understanding is once you've got a skill to 99 your next general goal if you wish to continue to train in a skill is to generally push for 120 skillcapes so my question is this why did they stop the content at an arbitrary halfway stage and not push content till its conclusion at 120?

They were able to fill the gaps for Dungeoneering, Invention, Slayer, Herblore, Farming, Archaeology, and Necromancy to 120?