Yes, by several orders of magnitude. The problem isn’t just browsers, it’s the massive pile of code that runs all these systems on the backend, many of which run on honest to god mainframes. You’re not going to flip a switch and get decades worth of software to run quantum proof encryption.
Wouldn't it just need to be the network transport that needs to be updated? I don't imagine the mainframe databases are encrypted-at-rest as it is, so how would quantum change anything there?
Yes, it’s mostly network transit that’s the problem. The issue is that there is a lot of network transit behind the scenes that’s not going through nginx and a client browser.