As an employer for more than 20 years in the tech sector, here’s my perspective on employee premium payments:

The only functional difference between the employer paying $100 toward health insurance, versus putting $100 in the paycheck and having the employee pay that $100, is that in the first case the dollars are tax-deductible for the employer, while in the second case the dollars are taxable income for the employee.

For the employer to pay the premiums just makes sense.