1 carat is not necessarily better than 2 carats, but chances, are one is a better carat weight for you.
A 1-carat diamond is noticeably smaller than a 2-carat diamond, but it’s not a 1:1 ratio. Some diamond shapes maximize their carat weight while others hide their carat weight. If you compare a 1-carat Oval cut diamond with a 2-carat Cushion cut diamond, for example, the size difference wouldn’t be as significant. But a 2-carat Round Brilliant cut diamond will appear roughly 50% larger than a 1-carat Round Brilliant cut diamond.
Size aside, a 2-carat diamond will cost significantly more than a 1-carat diamond of the same or similar quality.
If you prefer smaller diamonds, or the budget is more important to you than size, then a 1-carat diamond is better suited to you.