I've never seen or heard anyone major use GraalVM in production. I only hear Oracle and a small bunch of other folks hyping it. Tech also lives on hype and a long time until a tech reaches a critical mass is generally a band indicator (i.e. if something doesn't reach the mainstream in less than N years, it never will).

There are some exceptions (Ruby took off after Rails was launched, Python was adopted by Linux distributions and it also had some decent web frameworks such as Django), but there's a reason we call exceptions exceptions. It's because they're exceptional, they're not the norm. Plus in the internet age (I don't count anything pre-2000 as internet age, since dial-up wasn't something most people wanted to live through) it's a lot more likely for something with a great future to be adopted quickly.