7 years seem to be a long time, but for something that operates on such a low level it isn't. Rust also exists for 12 years now, but got the most traction in the last 2-3 years. From my point of view wasm is currently in a state where a lot of companies and people are learning. Most of the toolchains had to mature before the broader mass of developers (who have an interest in this technology) took a look into it.

Yeah, you are right, it is lesser used than e.g JavaScript, but tbh it also has a different target audience. You probably can build UI by using wasm. But why don't use JavaScript, which is way more comfortable and has a bigger community around it? (Unless you have some specific needs) As a web developer you don't need wasm right now. If you are doing some lower level work (like trying to run AI models/training) and you really need the performance, then wasm gets pretty interesting.

Most of the cool wasm projects I've seen in the past few months/ years were open source ports of games or emulators compiled to wasm (like Doom 3 ), which really ran very great. And my guess is that the broader development community is currently doing exactly this: they are playing around with wasm to learn for what use cases wasm could be a great fit.

(more known Wasm users are for example Figma or Google Earth. Iirc I've read that BBC is currently exploring if they can use wasm for their media players)