That is exactly our situation. We went to 13 two times so far, mostly due to saved-up 10s before the patch. A 13 is the highlight of the week… or month… if we get there, nearly everyone needs the gear and many hours of down- and upgrades flew into getting it, at times. No way this is gonna be a “practice-shard”. With getting 10s it is a bit different, but the risk is still high being stuck there and start over, lots of times, without getting anywhere.
One of the reasons that progress is so slow is that we are still stuck at temple 7 or so, plus the problem of finding 5 each evening capable to do higher shards, in EU timezone, at all. I wished we had a group practicing all this until the cows come home like abc did in former times, but that’s never gonna happen. Instead there’s constantly guild members leaving once they got bored with that jo-jo of shards or the game overall and the need of training new members until they get there.
And again, fully agree to 2., if one person says it’s not worth it or they hate the activity, then we all don’t, why should we.
PS: The idea of going without healer points to a fundamental flaw of the entire game imo, persisting since the OG. If more than the intended number of dps is necessary to advance in time or in 15, even with high dmg groups, same as using unintended mechanics everyone got used to, same with the need to kite bosses so they can’t onehit you (specially in the raids - it was a common, “usual” tactics in the OG raid and in the Reborn HMs alike), if that is what people rely on then it points to the fact that all this content is tuned up too high imo.