Is it advisable to get hemisection done in a molar with crown and abscess?

Hello doctor,

My crown has become loose as there is decay inside the crown and around half the edge but not visible. I was told that the tooth is stable underneath. I saw one endodontist who said to rule out the implant and that he would do a root canal but bone and gum are less than ideal and 50-50 chances are there that it will work. He also did not clear all the decay, did not take the crown off but drilled straight through. (A wobbly decayed tooth underneath the crown?), did not do the post or crown. There is a long-standing chronic abscess at the root for years. The current root canal was done 7 years ago. I do not have any other molars left in the lower. I am 60 years old. I was shocked, sad, and anxious.

I feel tempted to go to an unknown dentist just to see if he could do a hemisection as the Endodontist I talk to "no longer do them as implants are available and hemis tend not to last long". Does anyone reading this please see any hope for this tooth? I chew on it and have no sensitivity and no pain; no symptoms at all. There is a gum recession I have complained to the dentist about for the last couple of years. I am concerned I will regret not trying to save this tooth if at all possible. Also, I was told to see a prosthodontist to ensure a crown could be made if I get the retreatment. I have two tracks I am pursuing. I will see an oral surgeon tomorrow to rule out an implant and then see a prosthodontist. I am attaching X-rays. Concerned in this decision-making process about any further damage being done to gum and or bone. Impeccable hygiene history.