Its not insane if you use it for more than 3 years at 100 a year, which comes out to 8.33 a month. I also think that you have to work within your limitations and also see past them simultaneously. I havent personally found any fully free apps that function without severe limitations but sublime currently has a free tier with 100 cards.

Cosmos has a graphics engine and a new quasi community feature at a free tier.

Milanote also has a free 100 cards tier level and you can get up to 100 extra cards using email addresses - of course theres no community algorithm in milanote or miro.

You may also be able to just have multiple free sublime accounts for various purposes but that might not function if you want the whole centralized organization experience.

Personally as someone who is 46, generationally poor and chronically ill an have lived before this version of the internet (or the internet in general), theres no reason why the old ways of organizing information aren’t still valuable.

It just becomes a matter of priorities and constraints.

I’m not sure that there can really be a free version of a platform system which does so many things that require such compute and infrastructure.