First, a minor correction: The direct object of verbs take the particle を, not お (both pronounced the same).
Second, and more to your point, 好き is not a verb in Japanese the way that “like” is a verb in English.
There is a verb that means “to like” in Japanese; it’s 好む(この・む).
A direct translation of “I like x”, would be something like「私はxを好む」.
This just isn’t a very common way to express the idea in Japanese.
好き is an adjective which, in English, means something like “agreeable”.
A direct translation of「私はxが好きだ」 would be something like “As for me, x is agreeable.”
This just isn’t a very common way to express the idea in English.
So が isn’t really being used instead of を; it’s just that the common phrasing of the idea in Japanese (adjective based) is different from the common phrasing of the idea in English (verb based).