I was under the impression that the injunction against playing cards was because of their proximity to tarot/occult practices. Mormons had the same injunction against playing cards until the 80s, when the teaching was no longer promulgated. Speaking as a former Mormon...

Here in Sweden, where we also have free churches such as Baptists, Laestadians etc., the concern was definitely about gambling.

I think that's not wrong. Same principle, different sin... it looks like gambling, or the occult, or...