Why is the pronoun ‘I’ the only pronoun that is capital by default in English?

Question

Why is the pronoun ‘I’ the only pronoun that is capital by default in English?

In: 2109

Answer 1

From Google: I began to be capitalized mid-13c. to mark it as a distinct word and avoid misreading in handwritten manuscripts.

The reason for writing I is the orthographic habit in the middle ages of using a ‘long i’ (that is, j or I) whenever the letter was isolated or formed the last letter of a group; the numeral ‘one’ was written j or I (and three iij, etc.), just as much as the pronoun. [Otto Jespersen, “Growth and Structure of the English Language,” p.233]

Here’s the link to the full article if you’re interested:

https://www.etymonline.com/word/i