Those flasks can actually be really nice compared to normal RBFs for real reasons and not just memes. They are a lot easier to e.g. pipette out of because the taper gives small volumes of liquid more height than a typical round bottom, so less material is lost as skin on the glass. Same issue with stirring; it's a lot easier to get better stirring when the liquid actually covers the stirbar. "Just use a smaller container", you say, and yes, do so if you start with a small volume. But a lot of times in organic chemistry, you need to isolate the compound from solution by evaporating the solvent. Depending on the concentration, the volume can start large and end much smaller. These flasks can help recover a larger amount of precious material.