> Making a complete font set can easily take as long as a year. The tasks include to go from 'A' to 'Z', upper and lower case, plus all the glyphs (brackets, ampersand, exclamation marks etc).
That's when you're limiting the font to purely English usage. If you want to support any other language you have to add more characters, even for languages that also use the latin alphabet (e.g., French, Spanish, Italian, Portuguese, etc). Then you may want to support Greek and Cyrillic, Japanese, Chinese, …
For example, “Noto fonts cover over 77,000 characters, which is around half of the 149,186 characters defined in Unicode 15.0” according to the font's Wikipedia entry.
That's when you're limiting the font to purely English usage. If you want to support any other language you have to add more characters, even for languages that also use the latin alphabet (e.g., French, Spanish, Italian, Portuguese, etc). Then you may want to support Greek and Cyrillic, Japanese, Chinese, …
For example, “Noto fonts cover over 77,000 characters, which is around half of the 149,186 characters defined in Unicode 15.0” according to the font's Wikipedia entry.