lol Lux support is mostly played by people who hate support. We actually despise the role so we play something that is still fun. now are there the cancerous players who steal literally everything? yes. they exist. but the majority of lux supports are players who want to actually feel relevant in the game while still doing their best to help the adc.
I have played a few supports in my time and to be honest. my bot lane gets absolutely dominated if i play thresh or some normal support. but if i play Lux or AP sona then i actually am able to bully out the enemy adc giving my adc an easy farm lane and the ability to approach perfect CS for about 10-15 min. Many people just dont understand how to be relevant on a champion that does literally nothing outside of CC and i count myself among them. Im a jungle player so my entire philosophy is the 3 role system. Damage, Tank, Healer. This is why i literally cant play thresh. i do no damage, dont really have healing, and due to shit support itemization im not really all that tanky. This is why I play Damage supports like Sona or lux. Often times When in bot lane im doing 60-70% of the damage in fights, because q, e, r. on lux does enough to 100-0 someone.
TLDR: most Lux supports mean the best its just they are incapable of playing CC bots. and i count myself among this group.