Is HTML5 app development relevant right now?

Does it relevant to develop apps for HTML5 in UE4? Because it (Developing HTML5 Projects | Unreal Engine Documentation) says:
“As of Unreal Engine 4.24, support for the HTML5 platform has been migrated out of the engine to a public Platform Extension that can be maintained and improved by community members. Documentation for the HTML5 Platform Extension is hosted alongside the GitHub repository.”

Additionally, i found the Cloud Deployment “Pixel Streaming”. Is it supposed to be similar way for developing web and mobile apps?

Is there another HTML / web standard in the works? If yes, then it may be appropriate to learn that too. I would think HTML5 is still quite prevalent and in UE4, it sounds as though developing for it has become a more platform-oriented workflow and basis of support. I’m interested in creating a PS4 / XBox1 game, and those are unavailable in the engine editor by default as preferences or settings, at least in the standard version of UE I installed. It revolves around getting a different build of UE to get access to the tools, standards, and such for those platforms when developing. I don’t know exactly how to do it yet, but it’s something along those lines.

One area it might clash with is mobile and other browser-based languages that support developing games, video, visualization, interactive experiences, etc. JS libraries, python, and similar languages are what I’m referring to, but those have HTML5 compatibility / flexibility to and extent too.