My response to "grand vision" projects is to say, "work up an actual spec of what's necessary, and I'll respond based on what's technically feasible." I find that when they finally get their heads out of their entrails, most needs are very simple. Animation can be done in .gif, static images can be supported by imagemaps and tables.
But it will need to be the same experience that the client asked for. Coke is never going to ask you for a react website with webpack tooling and a lambda backend, they are going to come to you with some grand vision of an application that their marketing team imagined in the shower months ago and has been workshopped into a mess. You may or may not be able to deliver that with simple HTML and CSS.
I am also keen for the web to move toward some kind of stability in technology as well, the churn and wheel reinvention factory that we currently have is creating a bit of a mess but I don't think it's worth throwing the web away just yet.