Sounds like you've really exhausted your options then. Maybe one more thing you could try is decreasing your systemic inflammation with shit like glutathione, super clean diet, decreased upper body lifting, and the peptides/HGH on top. But that you would probably need to try for a long time for it to even be effective, and even then it might not work
type 2 acromion seems more susceptible to impingement pain than type 1 but less susceptible than type 3, so maybe that makes you a good candidate
do you know if you have a positive hawkin's kennedy test or neers impingement test? Your PT probably has done it on you. If not, look it up and have someone do it to you. The movements those tests do cause impingement by the position of your bones, so if your tendons are indeed getting impinged and inflammed/painful, those tests would hurt. However if you don't get pain from that, then your tendonopathy is not coming from impingement and it would be a retarded decision to get surgery for it
Although anecdotal reports might be interesting to read, I think you should look up some studies. That would give you more widespread data. Just go on pubmed and google scholar, combine subacrominal decompression with other keywords like "outcomes", "sequelae", "recurrent pain", shit like that. Remember systematic reviews and meta analyses are king. Also more recent studies are generally better
Heres one study on 180 people that showed "Major improvements in pain/function were seen at mid- to long-term after isolated arthroscopic subacromial decompression"
Long-term results after surgical treatment of subacromial pain syndrome with or without rotator cuff tear - PMC
Also make sure you trust your surgeon if you decide to go through with it. If he is literal scum of the earth, maybe he would fuck up your shoulder more so you would go back to him for more surgeries and thus give him more and more paychecks. And you may never know if he does it on purpose because its known sometimes people just come out worse after surgery