Gross income CHF 120'000 minus deductions you end up with 100K taxable income and the total tax burden (federal, cantonal and communal) is about 11K.
Edit: the same example for a canton with higher taxes (Bern) gives a total tax burden of 22K
[0] http://www.estv2.admin.ch/e/dienstleistungen/steuerrechner/s...
$100,000 income at 20% tax = $20,000
$35,000 income at 40% tax = $14,000
Switzerland's median income is between 2.5 and 3 times that of Italy. They have a smaller black market economy than Italy, so they're likely deriving a higher actual share of taxation out of it.
Further, the 16% referenced isn't complete. If you cap out the federal income tax in Switzerland, it's more likely you're paying a total of closer to 25-30% in income taxes (depending on what part of the country you're in), between federal, cantonal and municipal income taxes.
Also there are lots of hidden costs. Health insurance and mandatory unemployment insurance etc. A lot of stuff is pushed onto the private sector but made mandatory, so you have to buy it.
Taxes can be low if everyone (no matter their size, big or small) pay them.