\boldsymbol from amsmath:Boldface does not work on Greek letters because most fonts do not have a bold version of Greek letters. This is because bolding a letter requires thickening the strokes of the letter, which can be difficult to do for complex characters like Greek letters.
Yes, it is possible to make Greek letters bold by using a different font or by manually editing the font file to add a bold version of the Greek letters. However, this may not be a viable solution for all situations and may require technical expertise.
Bolding certain text is often used to emphasize and highlight important information. In scientific writing, Greek letters are commonly used to represent mathematical symbols and equations, and bolding them can help to make them stand out and aid in understanding.
One workaround is to use a different font that has a bold version of Greek letters. Another option is to use a different symbol or notation, such as using a bolded Latin letter to represent a Greek letter. However, these workarounds may not be suitable for all situations and may not accurately convey the intended meaning.
Fonts are designed by individuals or companies, and the decision to include a bold version of Greek letters may depend on the intended use and audience of the font. Some fonts may prioritize having a bold version of commonly used Latin letters, while others may cater to a more scientific or technical audience and include a bold version of Greek letters.