yea he's useful for emotional support but you don t like him in a attraction/sexual way. you find support in other people, better self esteem and his value lessens to the point he s no longer useful

you already know the answer, there s no point in extending this relationship when you never even loved him nor even think about marriage or children. at best you'll have a dead bedroom marriage at worse who knows. both you and him deserve better

if he does not engage for whatever reason you'll have to carry the burden and start the conversation. it surely would be easy if he did, talking about the things you are doing that annoying so you could skip the real reasons the relationship is ending but life sometimes is not that easy

best of luck