It's a little confusing and there is enough difference to have a different category. Or am I missing a category that has 100% ingame, but has a different name?

The community agreed on the 100% definition. 100% ingame is just map, so its a rather stupid grind. It still would have all 900 Korok Seeds, but wouldn't track dungeons, quests, etc. - just super arbitrary. One category of this length should be enough.

'This length' could be cut enormously by skipping all clothes and upgrades, all mini bosses, horse bridles and saddles and random quests. You'd still have to finish the dungeons to have 100% ingame. But if 'the community' has decided already, there is nothing more to say for me. Sorry for making this thread.

Nah its completely fine to ask. Dungeons are not tracked by 100% ingame btw - you have to unlock them, but not finish.