• https://www.bts.gov/content/average-age-automobiles-and-trucks-operation-united-states
• https://www.bendix.com/en/products/vehicle-dynamics/

Some probably do, tech has advanced quite a bit since I started driving in 2008, but the newer tech tends not to be installed widely when it first comes out due to how unreliable tech becomes under the working conditions that are normal in the trucking industry. Fleet owners want their equipment on the road making money, not in the shop costing money, so they tend to wait till a tech proves itself to be reliable. Plus upgrades costs money, so they tend not to happen till a unit is replaced with a newer model, which can take a while.

Most large companies in the US have an experimental fleet where they try out new tech first, before they roll it out to the rest of their fleets. They are looking for cost effectiveness, reliability and driver response. The smaller owner operators, which make up the bulk of the trucking industry, tend to follow (slowly) after them. And as old as the trucks are, the trailers are often even older. While most trailers in my company's fleet are less than 3 years old right now, the oldest trailer (now mostly used for hauling pallets back to Chep) was built in 1992 according to it's data plate. If it's ABS system is newer then 2008, when it was last active in the fleet I'm a monkey's uncle, and I'd pay long odds it's still the original system from 92.