CTCSS is older and more prone to spurious noise opening the squelch - weather or ambient. Additionally, there are relatively few usable tones. DCS is newer was was designed to address those shortcomings.
Both came out of Motorola, who initially was one of the only manufacturers of radios with enough frequency stability to use DCS (though others caught up quickly). Even today, some Baofeng as they age have trouble with a DCS system. Also, many older radios can't use DCS at all, and a few transitional models needed modules to enable it (usually you'd swap our the CTCSS module to a dual mode module).
So, yes, DCS is better, but CTCSS more compatible.
