CRAM is a standard that was started at Sanger/EMBL/EBI and developed freely in the open by the genomics community over the past decade. As others have told you, it is royalty free and unencumbered. The work behind the first version of the standard was published in 2010 (https://genome.cshlp.org/content/21/5/734.full). Since then CRAM has undergone many revisions and improvements from a plurality of sources, and is widely adopted among users whose use cases demand genomic sequence compression.
MPEG-G at this point is a three year old attempt to patent troll the genomics community and grab money. The people involved are not experts and are not aware of the actual state of the art or motivating requirements in sequence compression, and are instead trying to dance their way around prior art, as evidenced by the contents of their patents and presentations.
There is no equivalency here to fit your worldview.
Some of the MPEG-G authors are experts in genomics data compression, while others are experts in video compression. It should, in theory, be a good mix.
MPEG are also well aware of the prior art. The authors of various existing state of the art genome compression tools were invited to one of the first MPEG-G conferences where they presented their work. Do not assume because they do not compare against the state of the art, that they are not aware of its existence or how it performs. It's more likely simply that "10x better than BAM" is a powerful message that sells products, more so than "a little bit better than CRAM". It's standard advertising techniques.
MPEG-G at this point is a three year old attempt to patent troll the genomics community and grab money. The people involved are not experts and are not aware of the actual state of the art or motivating requirements in sequence compression, and are instead trying to dance their way around prior art, as evidenced by the contents of their patents and presentations.
There is no equivalency here to fit your worldview.