Chains are better. Every timing belt change is another expensive opportunity for an even more expensive error.
I’ve noticed that manufacturers seem to be returning to chains for 4-bangers. Hopefully they’ll return to all engines, although in DOHC V-style engines the chain has to travel a more convaluted path, adding some complications to controlling the chain at high RPMs. Chains have much more weight, and at high RPMs they want to form a circle. But it really isn’t that big a deal design-wise, it’s more that chains are more expensive to manufacture in than are belts.