I'd risk to say it's also quite a business niche, I can't remember what are top players making but they are definitely not doing this purely for entertainment.

Even if we assume it's purely for entertainment, the ecosystem is driving flow of goods (chess boards, chess pieces, chess lessons for kids etc.). I remember seeing chess set in chess shop on Baker Street in London with 1k price tag (and I think this one was not the most expensive they had)

Sports are played for entertainment, that doesn't mean that there isn't a huge business around it.