I feel like part of the reason why software engineering projects are hard to estimate is this. So you want to add video chat.. - this blogpost: 100 loc - pion (open source): 100k loc? - dolby.io/ agora: I'm guessing >1m loc - zoom.... even more?
It would be better if this sort of thing was heavily caveated ("this is the Hello World of WebRTC") because otherwise a lot of people (non-technical types, junior engineers) see it and think -- well we can do that, should take us a few weeks max.