IME the modern web is not amenable to user scripting like it was ~10 years ago. Then, most things were a simple static HTML document, more templated then generated. Now virtually everything (whether it's useful or not) is a heavy complex "app" that pops in at various times, only has arbitrary/volatile identifiers, and is generally harder to interact with as a user script.
jmadeano|3 months ago
And that isn't even to mention all the guardrails the sites put in place today: content security policies, untrusted html, dynamic refreshing, etc.