As an editor of the JPEG XL spec, I fully agree that ISO's paywall policy is bad in many ways.
But I wouldn't say it's a "closed" standard. Not any more closed than, say, the C++ standard or the Unicode standard. What makes a standard open is not the price the publisher puts on the copies, imo, but how transparent and open the process is to design and change the standard, and whether it is possible or not to implement and use the standard for free or not. In that regard, I would consider JPEG XL just as open a standard as C++ or Unicode.
The HEVC spec is publicly available without paywall, but you cannot freely implement and use this standard since it's a patent encumbered, very non-royalty-free codec. I consider it a closed standard for that reason, and the spec being available for free (but not implementable without paying royalties) does not make much of a difference imo.
But I wouldn't say it's a "closed" standard. Not any more closed than, say, the C++ standard or the Unicode standard. What makes a standard open is not the price the publisher puts on the copies, imo, but how transparent and open the process is to design and change the standard, and whether it is possible or not to implement and use the standard for free or not. In that regard, I would consider JPEG XL just as open a standard as C++ or Unicode.
The HEVC spec is publicly available without paywall, but you cannot freely implement and use this standard since it's a patent encumbered, very non-royalty-free codec. I consider it a closed standard for that reason, and the spec being available for free (but not implementable without paying royalties) does not make much of a difference imo.