I've seen the video Where the "comic book font" came from and it looks like the today's comic book fonts perfectly fit to the context of comics.
What are the key features that makes the comics font the comics font?
From a technical standpoint the font looks like it does because back in the day comics' text balloons were "speedballed" with, you guessed it, Speedball pens, which were THE standard for quick, jobbing hand-lettering from about WW1 until the computer made jobbing work look outdated and cheap.
From the Speedball site:
In the early days of the twentieth century, lettering signs, show cards and movie titles was laborious and time consuming, due to the only available tools – small brushes and fine pens. Letters needed to be outlined and then filled in . Ross F. George, a frustrated young letterer with his own shop, The System Service Company of Seattle, looked for a method to improve the speed of his work. His search led him to develop a nib with a reservoir, which he worked on perfecting with famed letterer William Hugh Gordon. It was nicknamed “Speedball” because of the speed of the pen, which reportedly cut time working in half.
The first pen points they products were the square ”A” style nibs, followed closely by the rounded “B” nibs, and not long after by the broad-edged “C” style and oval “D” style nibs. Over the years, the Hunt Company grew with the production of lettering, artists’ and mapping pens, and succeeded in capturing and keeping the major share of the market. The name “Speedball” became synonymous with lettering pens. In 1958, the Hunt Pen Company opened a new manufacturing plant in Statesville, North Carolina where the pens are still manufactured today.
I still have plenty of the Speedball nibs in my kit, along with a few lettering brushes, turkey quills, pieces of bamboo garden stake, and pointy nibs, because in the days BC, I did a lot of jobbing lettering for one-off signs, showcards, etc., as well as non-lettering work for reproduction.
In the example font, I see the work of the type D nib, which like the C is a "chisel" point, the stroke changing thickness according to direction. But unlike the C's, the D's stroke never becomes very thin, so there was no danger of dropout during repro.