Same here, was skeptical at first but then I used a web app that supports WebUSB to configure my mechanical keyboard and it lets you flash the firmware right there from the browser and that’s pretty nice and convenient.
Even before WebUSB, I was using ZSA Oryx to create my keyboard layout for my first ZSA keyboard. But back then I had to download the file and then flash it using a dedicated program on the computer. Now with WebUSB I could both create the layout for my new ZSA keyboard there, and flash it from there without any additional software other than a Chromium based desktop web browser.
https://www.zsa.io/flash
Even before WebUSB, I was using ZSA Oryx to create my keyboard layout for my first ZSA keyboard. But back then I had to download the file and then flash it using a dedicated program on the computer. Now with WebUSB I could both create the layout for my new ZSA keyboard there, and flash it from there without any additional software other than a Chromium based desktop web browser.