Yeah Java... Uhhh. I've been happy to start uninstalling Java now that Chrome and Firefox don't support it.
Unfortunately, a lot of network management interfaces are in either Java or Flash, and the equipment is old enough that no more time is being spent on development. The web interface that Motorola created for their WiNG Wi-Fi solution started life as Java based in 4.x and then went to entirely Flash based in 5.x. This is no longer owned by Motorola, and is now in the hands of Extreme Networks so I expect that will change for newer equipment, but not for older equipment still in use. Quite a number of NMS'es are Java applets, but that's slowly changing. Java applets don't run inside of the browser, but you do usually have to get to them by going through a browser.
Back on topic...I like the management interface Ubiquiti has created for their EdgeRouter products. You don't usually have to get into the CLI too much. I think it could be better, but I've definitely used much worse. And they've just started marketing their Amplifi
product. Looks like a neat idea, except that it requires the use of a smart device app to manage it. I'm also not sold on mesh Wi-Fi. Seems to me it would add latency, where Wi-Fi already has plenty of latency to begin with.