ever thought about bringing Safeguard/Aromatherapy/Heal Bell back into the meta?
short answer: yes we'd love to, but if it was that easy, they'd be much more common already
any team would love to carry a cleric if it had room lol. you have precisely two OU options, however: celebi or pink blob. there's a reason why most of the other choices are lower tiers, eg roserade, lanturn, miltank, lilligant, shaymin. having to find room to fit one of these onto a team is quite strangling in and of itself.
in addition, the two OU users (blobs/celebi) are EXTREMELY moveslot cramped on defensive sets. in addition to a damaging move (giga drain/seismic toss) and their recovery (softboiled or wish/recover), they have a broad selection of support moves, only a few of which they can carry. cleric support is often the easiest to throw away out of all those slots, since they need the slots just to protect themselves (protect for wishblobs, twave to prevent being set up on, toxic to stall, perish song because fuck BP). where does the heal bell fit in? the answer is that it does not. that's why they're so rare... even on stall.
oh and while i'm here: there are really only a few defensive ghosts worth running; fitting them in is easier said than done. jellicent is legit, but bieng water type means that it type stacks horribly with any other bulky water (eg tentacruel). sableye is precise in its utility, but pretty much pointless outside it - lacking in bulk means it's generally only useful to spinblock or stallbreak (i am painting a very negative picture here, but tbh sableye is awesome, use that shit it's good). cofagrigus ... ehhh, no reliable recovery makes it tough in the long game because pain split really sucks. same with dusclops except even more so.
interesting on altaria, although i am kind of agreeing that any defensively invested dragonite with subroost will be bulkier (subroosts tend to be the nites that abuse multiscale most infuriatingly of all). both of them are fairly G-weak though which is often of capital concern T_T i generally use latias (it is my favorite mon evar) since i don't wanna be trying to squeeze in more than one dragon on a defensive team.