First, you're talking about a full-fledged game engine (and one that's not actually free or usable by many projects, BTW!) by a huge team that can optimize individually for each platform (and doesn't actually support some platforms at all, e.g. Mac;
you may not care about supporting such platforms, but that doesn't mean everyone can afford that luxury). I am talking about a portable low-level graphics API that smaller development teams can use to build their own stuff without needing to rewrite their pipelines for each new target platform.
Second, you're also talking about a game engine that does not portably expose ray tracing GPU features; stuff like Nanite that optimistically takes advantage of the hardware where it's available to accelerate ordinary software rasterization is not even close to the same thing. This is a really weak argument. The truth is that neither you, nor I, nor (right now) anyone else knows how to expose that hardware portably, it's all incredibly custom and will probably need big rewrites for each new hardware release. You're complaining about an API not doing something that nobody actually knows how to do yet.
Finally, not every application wants to or is able to be rendered in the cloud. It's incredibly expensive to rent out GPUs if you're not being subsidized, and in fact even most AAA attempts haven't worked out economically. Plus not every application can deal with the server latency, or wants to be beholden to an always-online server, or has clients who can tolerate the bandwidth required, or a myriad of other things. So that isn't a solution to a portable low-level graphics API either.
I'm not saying WebGPU is perfect, but driveby comments like yours that imply it's missing obvious stuff or handicapped or whatever are pretty annoying. It's a very good attempt at a very difficult goal (efficient, portable, low-level graphics) that has value to a lot of people. It isn't going to be everything to everybody (and neither is UE5, incidentally). When there is a portable way to expose raytracing functionality I have no doubt it will come to WebGPU, but until then it's basically a meaningless gotcha.