It seems user-centric to you know... make the browser work for what users what to use it for. Like generating digits of pi.

Yes I'm sure there's a lot of consumers that want to calculate large amounts of digits of Pi in their browser..

I didn't say that. You're moving goalposts anyway. Calculating pi isn't the only use for big ints. The more practical application is maybe crypto or something.

But some users want to do it.

Given their $$$ seems like they could do both.

I don't think BigInt is some adtech anti-feature.

Safari also does releases less often than Chrome/Firefox. They are behind, but not by that much.

Given the recent influx of iOS exploits that have centered around WebKit they should probably adjust that priority

Will adding developer-centric features help reduce vulnerabilities? Generally adding any feature would increase vulnerabilities because of the increased surface area.