Benefits aren't nebulous, they're concrete things. My employer offers a pension(401k) contribution, health insurance (which is a queue skip really here), income protection for long term sickness or death in service, and a "perks card" which is 95% crap but gives me a 25% discount on the largest gym chain in my area. That's just monetary.
On the "non-monetary" side, I'm guaranteed 33 days _paid_ time off (and promised 40 this year), have an option to take a month _unpaid_ with notice, I have employment rights and can't just find myself without a job with no notice or dismissed for no reason. There's also the "overhead"/admin work of managing a business and handling the tax affairs. Sure it's straightforward, until HMRC decide it's audit time.
> Contract work is a fundamentally different proposition and equating it to employment is foolish.
That, I agree with.