I’ve been building a full FSE theme from scratch and was surprised at how much of my design I was able to successfully replicate with the editor, theme.json and minimal-to-no custom CSS. Sure, it took a lot of tinkering, but I was impressed nonetheless.

However, as Jon mentions, the second you need to adjust something for a smaller screen (or bigger screen if you dare to try mobile-first design in the editor), you hit a wall. It’s particularly apparent with margin, padding, and block gap, which have no responsive controls yet. You can see this adjusted via CSS in the new theme on .org.

However, there are hints of improvements coming for responsiveness. Fluid typography and clamp() certainly have helped get typography in check, but there will always be circumstances where you need even finer control. Every other site builder has solved this, there’s no reason to think WordPress can’t or won’t. (I certainly hope so, as ~50-60% of traffic is coming from mobile devices these days!)

As quoted above, one of the best ways to push past these growing pains is to have as much dog-fooding as possible — using the editor and FSE to build for as many real-life scenarios as possible to uncover these blindspots.

Surface what you find, dig into some tickets, and be kind to the volunteers who spend their time making this free software better each day.