After setting up dkim, dmarc, etc. I've had no problems in the past decade except for one person using aol. I told him that his email was broken and if he wanted to receive my email he needed to fix it. I don’t count such things as deliverabilty problems, but as receivability problems on the other end.

I’ve never sent any kind of bulk email and I suppose my host has a good IP. Everything I do depends critically on email deliverability, often to addresses I’ve never sent to before, so if I had a problem I would certainly know about it.