Is companiable silence ok, or the death of a marriage?

Yes quite. Hence I said 'many men' and 'women tend to.'

The only thing that matters in this situation is how each party feels about the status quo.

My general point was it's quite normal for there to be a point at which one half of the couple looks outward a bit, rather than expecting another one person to meet all their needs.

There's nothing wrong with companiable silence provided you're both comfortable with it. I think I'd struggle to live with someone who needed constant verbal interaction.

I love companionable silence, but that doesn’t mean DH and I have nothing to talk about when we are feeling chatty. We’ve been married nearly 35 years and no kids, so had to find other things to talk about!

So if you go away, for example, will he discuss the hotel? Discuss what you've seen on the news? DH and I rarely discuss stuff now because we both know what the other will think!
I agree with the pp who said about you getting hobbies, etc. Rely on your friends for lively conversations.

Sounds like a good life stage, you talk when there is something to talk about, but also happy just being in each others company. Sounds good to me and not negative in any way, as long as you’re happy.

I'm a woman and I love companiable silence. It's so comforting to know I can sit with my DH, in silence, and not feel 'forced' to speak about anything.

It's not always a sex-based thing. Some people just like to 'just be'.

It becomes a problem when two people/the couple don't feel the same.

Should I just enjoy his company?

To me, this is the real question: do you enjoy his company? Or would you, if you weren't worrying that you needed to think of topics for conversation? If you don't enjoy a companionable silence with someone you know really well and feel comfortable with, but he does, that's an incompatibility. But it's plausible that he genuinely does enjoy feeling comfortable enough to be silent with you, which is not necessarily a sign of something wrong.

I always joked that we'd been married for a year before my husband spoke to me. He is quiet and only speaks when he feels that he has something important or interesting to say.

Now that the kids have grown up, it can lead to some very quiet evenings. I think it's mostly companionable but I can't deny that I sometimes look at couples who are chatting and so on and wish we were a bit more communicative.

But he is who he is. Our marriage isn't dead; it's just different to other people's. We all have to make our own decisions as to what makes us content. Or not.

I don't think it's automatically a negative. Many men are like this past middle age, and there's a lot to be said for companionable silence IMO!

You obviously need more, though, so I'd suggest you get that from friends, hobbies, going out and learning new things. Women tend to need much more social interaction.