I don’t know if you’re making a joke or not, but getting NHS isn’t worth $200,000 USD per year.

Most Americans get employer-provided health insurance, which costs money (the amount specified in the DD section of the W2), and its often in the $1500/month range. That DD amount isn’t part of your income or the salary Glassdoor mentions. It’s an added benefit of top of that.

In the UK and elsewhere, around $500/month/person in taxes pays for your healthcare. That’s essentially subtracted from your income. So the uk income is even lower when you subtract the taxes the NHS costs.