Porn addiction, although very real, is far too commonly thrown here on MN.
as others have said, if he is choosing porn over real sex, and the porn effects his day-to-day life - IE being late for work because he wanted to watch porn instead/before he left then he is a porn addict.
I’ve watched porn regularly, both in and out of relationships and it has never ever been a substitute for real sex.
Assuming he does have a porn addiction, he needs to address the reasons why. My porn use escalated during lockdown when I got Peyronie’s disease and then partial ED, meaning I couldn’t physically have sex. Is everything ok for him in that department?
he could be avoiding it for fear of not getting hard, or having PE, so porn is the easy way out, although certainly not the right way out. the fact that the type of girls he is searching for are similar to you, would suggest he still finds you attractive and it most certainly is not a you problem and it’s a he issue.
now you both know each other watches it, why don’t you bring it into the bedroom and watch it together? It won’t work for everyone, but it can certainly be beneficial for some.