King Gizzard and the Lizard Wizard (yes really) do this, but not just for people who buy tickets to the show. They have 444 concerts up on Archive.org for free to all.
https://archive.org/details/KingGizzardAndTheLizardWizard
Plenty of other artists have free concert archives at https://archive.org/details/etree
Sigur Ros have a surprising number of shows on their ftp, which is delightfully retro.
since they have been doing orchestral performances, getting to hear the orchestral versions of their old songs has been amazing.