Active listening is very noisy, we can be very confident they're not doing that at scale.

My whole point is that they're no longer able to do passive listening of unencrypted content and massive scale, but instead are forced to rely on much smaller scale active attacks.

You're making assumptions that are not taking into account all the other capabilities revealed in the Snowden leak and several other prior leaks. The name "Tailored Access Operations" alone should tell you something. They still have presence in all the large tech company's networks (with cooperation from them of course), and they are able to access critical servers like MTA's. The shadowbroker leaks are also another glimpse into their historical capabilities.

You're assuming that despite their budget not having changed meaningfully, no repercussions against anyone from the historical leaks, the continued renewal of the patriot act and unchanged mission of the intelligence community orgs that somehow they've wound down. That they've stopped R&D and tailored access ops.

You're also assuming that tailored access is not used to facilitate, correlate and enrich traffic decryption.

You look at things from your perspective where decrypting traffic alone is all too important. If you can see all the metadata, why would you do that? If you hoard 0 days and sophisticated implants what's the advantage? I mean half the time comms alone aren't enough, you want access to internal networks, documents that will never get transmitted over the network,etc.. smartphone telemetry data from a large group of targets. They're not interested in decrypting traffic to grandma visiting facebook, they want to know who's downloading tails, who's using signal, who's committing to interesting git repos, who the source of some journalist is, what people a politician has been messaging on whatsapp. Once targets are identified they can be implanted, or have their traffic selected for decryption.

But I think i get what you're saying, that most of the traffic they capture is encrypted. That much I agree, that has changed. But whether they can decrypt it on-demand, that is tough to speculate, whether they need to? That's what I'm disagreeing with. If their goal was that one-time traffic decryption, perhaps that has been curtailed with the prevalence of TLS and CT logging. But metadata alone is sufficient to select a target, and all the evidence suggests that even if they can't readily implant targets, they can successfully perform targeted MITM attacks, even with typical non-mTLS/non-pinned TLS setups.