The benefits of creating your own font are that you can draw the letters with the same hand that will draw the art, so the two go better together. You also get to control the "feel" of the font, and you can design it for a story where you are going for a specific tone.
For a font to work well in a comic, it has to be compact so that it leaves as much room as possible for the art, while it should stay readable. The x-height (height of the small letters) should not be significantly smaller than the height of the capital letters. This is probably one reason why comics creators often just use only upper-case.
I created the three fonts introduced below for my website. I named them Amsterdam". Amazingly, there were no fonts named Amsterdam yet! The most recent and best utility I found that can turn hand-lettered into a font, is www.calligraphr.com. I do then adjust the kerning using fontforge to improve the font further. The kerning is improved over time, a later version of the fonts below may have better kerning.
I offer the files for download, and under a very permissive Creative Commons license.
If you want to use the fonts on your website, you need to add the following to your css:
src: url('amsterdam_script.woff2') format('woff2'),
src: url('amsterdam_drole.woff2') format('woff2'),
src: url('amsterdam_goldenageserif.woff2') format('woff2'),
Amsterdam Golden Age Serifamsterdam_goldenageserif.ttf