Going to put a different take on it.
You could be describing my situation a year ago: he was approaching 30, never really had a serious relationship, outearned me hugely. I am a few years younger and have had past relationships and had certain timeline expectations.
At 9 months he hadn’t told me he loved me but I was confused as it was by far the best relationship I had ever had. Spending 2/3 evening and overnights together a week. He said he thought 4-5 years was a good timeline to move in and marriage after that!!!
I put all my cards on the table. Told him I felt loved but needed to be told it to feel secure. That I was willing to wait a bit to move in but 4-5 years was too long as we could be wasting our time! It turned out he just hadn’t been in a relationship before, hadn’t really given much thought to timelines and was just plucking numbers out of thin air and was also terrified of doing things too quickly.
He said he would give it some thought and gradually started to share his thinking with me. Initially he agreed to a weekend away, followed by a longer holiday a few months later.
He was given notice on his flat 3 months later and I was gobsmacked that he asked to move in. We spent lots of time talking about how it would work; divide of finances, dividing together time and solo time, divide of housework.
6 months later we are blissfully happy. We ensure that those conversations are ongoing so we have adjusted some of our original arrangements but we really love living together, even doing separate things. He’s not scared any more and if he is, he shares his thoughts with me.
What really mattered was him sharing the his thoughts. We’re starting to cover marriage now and he says he’s not ready but explains he wants to do another big holiday and hit some other milestones first.