Some do, some don't. It's not a set in stone thing afaik. Some old recipes are simpler than others. These days mostly always it's more than just meat(s), water, salt.
When have you ever heard of anyone discussing "Finnish cuisine"? When have you ever heard of there being a Finnish restaurant somewhere outside of Finland? I'm sure a couple exist, but most are probably "Nordic" and I'll genuinely be surprised if you find one that's a "traditional Finnish food" restaurant in another country.
I mean it's peasant food. Simple, fulfilling and imo pretty good for what it is. Karelian stew being a good example, though I've never actually had it as plain as you described.
Traditional Finnish cuisine isn't anything fancy but it's not really supposed to be either. And I don't mind, I like it.
An article about Finnish cuisine exists. Because as a concept, we can talk about it.
But in the sense of there being restaurants for it, like Italian, Mexican, Greek, Indian, Chinese, etc cuisines, I would bet quite a lot that you can't find one single restaurant dedicated to "Finnish cuisine" outside of Finland.