cleanse... why even bother

cleanse vs QSS. removes healing debuffs? Cleanse: NO. QSS: YES removes suppress? Cleanse: NO. QSS: YES. cooldown? Cleanse: 210 sec. QSS: 90 sec gives 30 MR? Cleanse: NO. QSS: YES. builds into one of the best damage items in the game? Cleanse: NO. QSS: YES. wastes a summoner spell slot? Cleanse: YES. QSS: NO. someone please explain to me a situation where cleanse is going to be more effective. the only thing i can see is if they have a lot of long lasting chain cc like morgana+rammus+fiddle+ashe or something like that since cleanse does give you the 65% tenacity after use, but even then, just a spellshield or even building normal tenacity or a QSS seems like it would be more useful than having to give up your ignite or heal for a tenacity boost on a 210 second cooldown. PS. its hilarious that riot constantly talks about how important clarity is to them and meanwhile is like "I CAN HEAR YOU ASSHOLES! don't lie, i'm not important to anybody"