Yeah it is ugly for sure, but it is stable and I like not having any straps contacting carbon. But yeah, most people would just pay their money and wait for shipping and not repurpose stuff.
Anyways, with a frame corner bag, you can fit a tube, tool, bacon strip kit, patches, zip lock of band aids, quick link, zip ties... anything pokey that I don't want to land on in my bib pockets. Some people get one of those mini pumps too, but I just have a frame pump attached to a bottle cage. Packless is nice. I also prefer to have the weight of the stuff of the frame bag near the front of the bike, instead of on my dropper or body.
Please don't take it as offense. Each of us have different needs. I started with the saddle bag strapped to the front triangle. Didn't work, and I didn't need that much storage anyway. Hence the very small packages spread across the frame.