Not sure who uses a 6' square of anything on the road unless they happen to have a tailwind and can use it as a sail, but yeah, I'm pretty sure the neon yellow t-shirts, hoodie and rain jacket I wear for my commute are more visible than a light in the daytime, primarily because their visible area is 50+ times as large as the lights.

The only regular reflectors left on my bike are a Cateye on the rack and the one built into the Radbot 1000. OTOH, there's reflective tape, heat transfer reflectives, reflective sidewalls and reflective trim in lots of places on it. Tape weighs virtually nothing, is still fairly effective for side visibility even when it's trimmed down to pinstripe widths, (I prefer larger for front and rear, but a lot of that comes from cheap eBay heat transfer on my clothes.) and doesn't have to look dorky if it's done well. (I may get around to redoing mine to look a bit nicer someday as the quick-and-dirty early stuff peels off.)