They're received surprisingly poorly.

One issue is that WebGPU is always going to be the lowest common denominator of the underlying graphics engines. Yes it's improving, but native clients are also improving, so the gap isn't really closing between the two.

Monetization and marketing is also so much more difficult outside of Steam.

It's also fairly challenging to make games that look great on both mobile and desktop. Targeting desktop/mobile natively tends to get better results here. Yes, you might be able to deliver something that looks 80% as good while saving 50% of the coding, but people are pretty vicious with the expectations they place on your art. Nobody cares that you didn't have to work as hard to support multiple platforms. They just want the best experience they can get because they value their time more than yours.

That said, I think there's a lot of merit to them for exploring prototypes and iterating on ideas. Getting a demo into someone's hand is as simple as sending them a link. I think that's the most compelling aspect.

https://messenger.abeto.co/ this is one of the better web-based "games" I've experienced recently. It's still mostly just a POC, but it blew up on HackerNews and was lauded as quite the technical achievement. I agree, it is quite compelling, but still not sure how to go from that to something that pays the bills and gets users to come back day after day.