Yep, it is a pretty big issue. However, WebGL does make it worse: it trivially exposes local privilege escalations as remotely-exploitable root vulnerabilities

Yep, it is a pretty big issue. However, WebGL does make it worse: it trivially exposes local privilege escalations as remotely-exploitable root vulnerabilities. It also does so bypassing a lot of the sandboxing work that browser vendors have done to contain browser vulnerabilities.