have you ever tried using an outliner such as Dynalist? im not familiar with mediawiki but i used Evernote for a long while. once I found out about dynslist i moved everything over in the space of a few days, even though it didn't have support for in-line images which I used a lot. the speed at which you can jot down notes made me not care about other missing features.
the other benefit of an outliner is that you don't have to worry about things getting unorganised. everything is a bullet point but you can also nest points under each other and then collapse the list or zoom in to focus on a certain point.
with a single page like in Evernote there is only so much you can write before things gets messy. if you want to reorder something it means you can to cut and paste whereas with dynalist you just drag and drop the bulletpoint
heres the full feature list
https://dynalist.io/features/full
or check out the showcase section in the forum to see what other people are using it for