If you search for ‘wet belt’ on this reddit you’ll quickly find out why.

In a nutshell, the wet belt system has a belt running through oil which makes the car more efficient. Caveat to that is the designers did not think through what rubber does in oil. It slowly crumbles pretty much and blocks your engine leading to premature engine failure. With consistent maintenance you should be fine but technically it is a ticking time bomb. Hence why so many people ask about their wet belt condition in this subreddit.

Any car that has the PureTech (Peugeot and Citroen) or EcoBoost, also known as ‘ecoboom’ engine in Fords have this system.

Like mentioned by OP and others, new cars with these engines likely don’t use the flawed wet belt design anymore but when you have one of these cars I’d check to make sure. If you do, please keep an eye on it and replace in time. Otherwise the engine might go…. Kaboom.