General was used earlier than generic, and the former has more meanings than the latter. General also appears much more frequently than generic, as shown in the graph below from the Collins Dictionary.
As can be seen from the figure above, the relative frequency of general is much higher than that of generic, and the relative frequency of general is relatively stable.
General, although derived from Old French, is English in C1200 was used. Its adjective suffix -al is also not added in English, since general is directly derived from the Old French general (12c.).Further onto the Latin generalis.
Latin, Old French, Middle English are all used. For example, in the Collins Dictionary of Advanced Scholars, there are five general adjective meanings.
The generic terms are relatively simple, and the Collins Dictionary of Advanced Scholars lists only two meanings.
The generic suffix -ic can be traced back to -ique (French) -icus (Latin) -ikos, but it was a word that was only used in the 1670s. The use of this term may be related to the development of British industry.
The first industrial revolution began in the sixties of the eighteenth century and originated in the Midlands of England. The Industrial Revolution was naturally large-scale production, while before the Industrial Revolution, small-scale workshop production was hand-made. In the process of changing from manual to large-scale production, versatility has been emphasized, and in order to deliberately avoid the ambiguity of general, generic was created. When generic is used in a product or manufacturing, it means not special, not brand-name.
Because it is not special, it can be produced on a large scale, so the cost will be greatly reduced, so generic also has the meaning of cheap packaging, in plain.
Of course, since generic and general are both adjectives derived from the Latin genus, both have "non-special meanings". And because the word generic was coined late, it is easier to think of race, kind, so generic has the meaning of a general kind.
"general" is often translated as general-purposed, presumably because general is so commonly used.