The other top level domains aren’t as credible, and everyone knows that.

credible? Ubiquitous, sure, but credible? Who ensures that a .com is a credible website?

Whoever said anyone ensures a .com is credible? I don’t think anyone said a .com guarantees credibility. I said, other tlds aren’t as credible, and everyone knows that.

They have 140M .com domains.

Everyone holding a .com domain can't simply move its registration from Verisign to somewhere else.

(Moving to new gtld is not equivalent at all)

They're holding their customers captive and profiting from it.

There's a cost to switching. Established links, domain reputation.

Oh, please. Technology is deflationary. Significant, repeated, above inflation price rises aren't the fault of users: it's the US Government enabling monopoly corruption.

Few beyond .com would be recognized by non-technical people

They're a monopoly on .com. Reasonable or not, .com is still widely seen as more authoritative than other TLDs, even .net and .org.

So why shouldn't Verisign be able to capture the value they're providing?

What value do you imagine Verisign provides? Verisign has nothing to do with .com's reputation. Most people have never heard of it. They didn't even run it until the peak of the .com bubble when everyone had already made their associations with .com.