I have Air Pods Pro and I bought an aftermarket silicone ear tip that was slightly smaller than Apple's small. The damn things still fall out, albeit after a longer time. They are always uncomfortable and I am constantly having to shove them in. I tried foam and they didn't fit either. I must have freakishly small ear canals. I wish I could find something that works for me. The article linked in the original article…
After trying several alternatives with similarly unworkable results, I just recently picked up the Anker Soundcore Life A2 NC and finally have wireless earbuds that are usable. The feature set is somewhat lacking vs. the Airpods Pro but is good enough for me. The sound quality is also a bit disappointing but still better than the frankly awful Airpods. I think there may be other options out there worth looking at for us small-eared folk with similar designs -- the key is rather than a big 'bulb' right behind the tip for the drivers and electronics, the bulky bit is set a ways out from the tip and is suspended without touching your ear in use, allowing you much more freedom in getting the angle and depth of the part in your ear canal just right. Instead of attempting to nestle that big bulb in your external ear cavity like the airpods do, it has a little stabilizer wing that is flexible and comes in 2 sizes, and they come with five sizes of silicone tips. I've been wearing them basically all day for the past week with almost no discomfort.