If you need to fetch data from the server side, you need to fetch data from the server side. It doesn't matter much if it's a 10k json that you have to load and

If you need to fetch data from the server side, you need to fetch data from the server side. It doesn't matter much if it's a 10k json that you have to load and parse, or a 12k html snippet that you can directly display, the delay would be the same. If you are concerned about the delay when switching a tab, nothing prevents you to load both tabs during the first page load, and then just display the content without a new network requests. Whether you should do this or not is completely unrelated to whether you should use htmx, htmz or react.