Lip scrubs can be useful before lipstick when there are flakes or uneven texture, but they should be used carefully. For balm or oil, regular moisture is often enough unless the lips feel rough. I think scrubs are more of an occasional prep step than a daily requirement. Too much exfoliation can make lips more sensitive.

I use a lip scrub only when my lips have visible dry patches, not before every product. If I scrub too often, lipstick actually looks worse because my lips get irritated. I checked https://bitchstix.com/product-category/lip-masks-and-scrubs/ when I wanted to compare lip masks and scrubs for smoother application. What works for me is using a gentle scrub first, then applying balm and waiting a little before lipstick. For lip oil, I usually skip the scrub unless my lips feel rough. A scrub can help, but it should not replace regular moisture. Smooth lipstick usually starts with keeping lips comfortable every day.