Quite so. As I wrote ..We should look at lux levels, not lumens.
As I've often said, whenever I have replaced fluorescent tubes with LED ones of the same length (hence around half the "lumens", I have always found that, at least perception-wise, the illumination is at least as good ('bright') as with the fluorescent. This may in part be due to the fact that the light radiation from an LED tube is far more directional.
As above, that has certainly always been my experience.Yes LED tubes often don't produce as many lumens as a traditional tube, but the lux on the ground may well be the same or similar. A modern 5ft ~20w led tube will nearly always be more than bright enough to replace a 5ft 58w traditional tube
Kind Regards, John