Before the Spanish showed up and WRECKED OUR SHIT, precolonial Filipinos all wore skirts, dresses, and/or loincloths. It is much easier to weave a single piece of fabric, or a single tube of fabric, than it is to weave the fabric, pattern the fabric, cut the fabric, and sew the fabric into breeches. Why would you do that unless you had a practical reason to?
There were occasional examples of what looks like breeches in the Boxer Codex, a late 16th century Spanish manuscript that contains illustrated examples of the attire of the various ethnic groups in and around the Philippines, (along with ethnic groups from other Asian countries), but irl most likely those were just malong/patadyong (a garment that is a tube of fabric) tucked and tied to create breeches.
Please enjoy the below illustrations.
(There is a critical lack of mention of hanfu, yukata, or hanbok on this post. I only have the expertise to cover hanfu, but I don’t have the strength, spoons, or enough expertise to feel comfortable handling that so I’m hoping a hanfu expert can weigh in!)