I tried to get someone to add the option for video responses back probably 3 to 4 years ago. They were a big part of what tied the community together and helped us find each other. The argument I got back was that youtube killed it because it wasn’t used much and once posted had a very short lifespan.
Tweets have an 8 second lifespan so by that argument tweets are useless.
They killed video responses because they were trying to make money and boosts the big channels over the rag tag communities we enjoyed that made them little to no money,
Discoverability on peertube is still sadly lacking, and if there was a mechanism to encourage people to make videos to respond to other videos and start a conversation and community it would encourage more people to post on the site. Right now there is nothing social about the platform, people just post into a void right now with little to no engagement. You need something to engage people and make them want to stay beyond watching the few videos on there people have bothered to post because they get little to no views.
Barring that, just placing a video response section, and then scraping the comments section for any peertube links and displaying them would help out a lot.