DP probably games for an average of 2-4 hours a day. We both game, often together, so he doesn't game and ignore me. I don't have an issue with it, but he's (nearly!) always pretty respectful.
If I need him to stop and help, or I just want to spend some time with him, he'll stop. He doesn't ignore my DC, and will pause or stop if they want to talk to him. If he wants to join a group thing, he'll check that I won't need him for something for the next 30 mins / hour / however long. He didn't do this one time, and I ended up sat on my own, eating the dinner I'd cooked for us both. Words were had, he was apologetic, and now always checks.
I know he loves gaming, I know it's his primary hobby, but I also know where his priorities are, so for us, it isn't a problem. If we had a tiny baby, or small children, it would be a lot harder though. He would need to be just as tuned in to the baby's needs as I was. If I had to keep asking him to tag in for bath times, or bed times, I would probably end up feeling resentful. Being made into the default adult, so one person can semi- check out, is a relationship killer.
How does he react if you interupt him, OP? What if you interupt him repeatedly? Does he still make you feel like a priority over gaming? Or does he get annoyed?