19 in Arabic numerals starts at the top left and takes two, maybe three strokes.
Also, a 1 followed by a five needs a lot of kerning to not get confused. And the vertical heights and offsets of the glyphs vary a lot.
Also the advantage of this system, for the people who designed it, is that it fits with their language's numeric system. According to the article it improves academic achievement for native speakers (don't know if that's true).
There's no suggestion that it's better for everyone or even that it's easier to write or read.
I'm bilingual and (more or less) speak/read a handful of
other languages. I also teach kids maths. The way your native language counts has a significant impact on the way you think about and learn mathematics.