All Microsoft Office products are moving away from Calibri as the familiar default font. Aptos, which first was known under the moniker Bierstadt, will become the default choice for every user within the next few months.
Calibri has been the default option within Word, Excel, PowerPoint and all other Office products since 2007. At the time, it replaced Times New Roman, which was the last serif font. That means it still had auxiliary lines at the top and bottom of the letters, improving readability. Sans-serif, however, is more aesthetically pleasing to most people, which will presumably have been the conclusion from Microsoft based on focus testing.
Back in 2021, Microsoft revealed five fonts that were in the running for the coveted position. After all, in the end, many users will not bother to choose another font, so countless documents will use it.
Out of these, the so-called Bierstadt emerged as the winner. Below is an example of how it was presented at the time. By the way, the other finalists may still be chosen within Office products.
However, many organizations are not very quick to make these kinds of adjustments. For example, The Verge points out that U.S. authorities have only since this year prescribed Calibri as a standard, which dropped Times New Roman.