My horse was diagnosed with EOTRH when he was in his late 20s. I didn’t feel comfortable pulling all his teeth at once. He was already a little fragile and taking him to the clinic would have been hard on him. I had a great dentist vet (Dr. McAndrews at Garden State Equine) come out and do a thorough evaluation and pull all the cracked/rotten/problematic teeth. I think 6 in total. He was IMMEDIATELY back to his old self. Perky and eating right out of the extraction. Over the next few years we kept a very close eye and he had a couple more extracted when they went bad. He passed at age 32 for unrelated reasons.
Adding complication, since this horse was young he would.not.touch.wet food. Nope. Not under any circumstances. Not bran mash. Not dampened grain. If a drop of water touched it, he was out. Towards the end he really couldn’t eat much hay, even chaff. He thought he was eating it, but he’d quid it up and it would all fall out. He did manage to eat non-pelleted feed, even when his teeth were at their worst. He was a very slow eater but he successfully consumed non-pelleted feed. Pelleted was hard for him to chew. Once he got the teeth pulled he could eat any grain but still quidded most of the hay. Luckily we have nice pasture for a solid 8-9 months of the year, so he was generally getting as much grass as he could intake in addition to the grain. For a little guy, I fed him a LOT OF GRAIN. Life would have been easier if he’d have been willing to eat soaked alfalfa pellets or similar.
Had he been less fragile/younger I would have pulled all the teeth at once. Because he was a little frail and I wasn’t sure how long he had I didn’t want to put him through that. On a less fragile horse I think it’s absolutely the way to go.