Except now replace "platform" with browser, and you have the exact same dilemma as if we still made desktop applications.
It's sad how many "web apps" (and even more regular sites) only work in Chrome - try using Firefox or any non major browser, and quite a lot of the web simply doesn't work.
Hardly the same. Desktop applications are still much more time-consuming to make. The differences between desktop platforms is on another planet compared to the differences between browsers, especially the difference between Firefox and Chrome, especially when you consider mobile.
It's sad how many "web apps" (and even more regular sites) only work in Chrome - try using Firefox or any non major browser, and quite a lot of the web simply doesn't work.