The entire purpose of an abstract is for fellow experts in the field to grok the paper quickly, not for the general public to get a hand-wavy interpretation of jargon.

And quite frankly, absurd practicalities aside, there is a lot of harm in having every paper accessible to all. There’s a wide divide between papers that have been accepted to a venue vs. important theory that has been debated and accepted by a scientific community and is worth presenting to the general public. And, the general public certainly cannot tell the difference.