The US doesn't have VAT, it has sales tax, which varies geographically by a great deal -- even between neighboring cities.
And advertised prices in the US virtually never include sales tax (in large part due to that variation).
Hotels and ticket brokers aren't getting any kind of free pass, they're advertising prices in the same way as everywhere else like grocery stores or Amazon -- at least as far as sales tax is involved.
Literally the only locations I've ever encountered that include sales tax in the price are a tiny minority of coffee shops (often cash-only) and budget pizza places (often the dollar-slice ones), which is to avoid having to deal with coins.
(The article is about other fees though, which is a different subject from sales tax.)