In an article with the most clickbaity article ever, Joe Honton does a nice job of talking about the evolving landscape of web development. "Full-stack" perhaps had its day as a useful term, but since front-end development touches so many parts of the stack now, it's not a particularly useful term. Joe himself did a lot to popularize it, so it does feel extra meaningful coming from him.
Plus the spectrum of how much there is to know is so wide we can't all know it all, so to get things done, we take what we do know and slot ourselves into cross-functional teams.
Since no one person can handle it all, the 2020 stack must be covered by a team. Not a group of individuals, but a true team. That means that when one person is falling behind, another will pick up the slack. When one person has superior skills, there’s a mechanism in place for mentoring the others. When there’s a gap in the team’s knowledge-base, they seek out and hire a team member who’s smarter than all of them.
So the "2020 Stack" is essentially "know things and work on teams" more so than any particular combination of technologies. That said, Joe does have opinions on technologies, including writing HTML in some weird GraphQL looking syntax that I'd never seen before.