I think the contrary is true. Frequency and phase matching is a feature, not a bug. Because AC gives you frequency, and frequency is not just easy to measure but also easy to have accurate references and very immune to noise, it is also not influenced by step-up/step-down transformers. This makes balancing an AC grid possible. Frequency below the set point? Increase power output. Frequency above? Reduce. As an added bonus, this happens to exactly match up with how synchronous generators work. So you get a fairly robust way for many distributed power plants to collectively coordinate power output without additional communication just by agreeing on the physical quantity which we can measure with the highest precision of any quantity very cheaply.

That is not possible with DC.