With nobody at Apple handling the engineering problem of implementing user requests, we're stuck with what we got. So I highly recommend App Tamer by St. Clair Software (no affiliation), which lets you set how much CPU percentage each process can use:

https://stclairsoft.com/AppTamer/index.html

It does cost $14.95 USD, but it's given me my computer back for years now. I have Spotlight Indexer set to 10%, although I'm using an old version of macOS and don't know if that's mdutil now or if Apple has outsmarted its throttling. I also set web browsers to 10% when they're in the background. And you can always message the developer with feature requests.

A bit of a rant: I honestly feel that we've done process scheduling wrong in most OSs and apps. It should have always been up to the user, along with granting permissions as needed. And I can't believe that no web browser has implemented turning JavaScript off after perhaps 10 seconds for example, so that we can have as many tabs open as we want. Instead we've let the technology order us what to do. It's all just so wrong. But the barriers to entry for writing a new browser are so high that only large organizations can do it, and they choose not to, so help isn't coming. Although I think with the arrival of AI, we're going to start seeing real software again that makes a mockery of the status quo and hopefully eats its lunch.

I ran into this yesterday. My entire machine was running slow. I checked Activity Monitor and it was mediaanalysisd running at 100% for about an hour. i couldn't kill it as it would just restart. A search said I was S.O.L. unless I disabled SIP. (can't, it's a work laptop)

Further, Spotlight is completely broken in Tahoe. I have all categories off in System Preferences except Apps because it's the only thing I use or want to use spotlight for, a quick way to launch apps. But as of Tahoe 26.2 or so Spotlight is showing tons of non-app results so it's no longer useful as an app launcher.

It's a shame Apple has decided that if the launch agent or daemon lives in the System folder that means the user/admin should have zero control over it. I should be able to disable any launchd job on my computer end of story.

Apple Configurator MDM profiles can control Siri behavior, e.g.

https://github.com/jankais3r/Siri-NoLoggingPLS

  Disable server-side logging of Siri requests for your Mac, iPhone and iPad

You can disable Siri (and Apple Intelligence) entirely via Apple Configurator or asking the nearest LLM for .mobileconfig file with:

  <key>allowAssistant</key><false/>

As hinted with the Finder comment, "Spotlight" is behind much more than the command-space search box. I don't know what the Siri services might do other than Siri itself, but wouldn't shock me if they were involved in things like Shortcuts and Control Center widgets. I understand thinking things you don't use are simply a "waste of CPU and storage space", but this reads like the kind of posts I used to see in the Windows XP era where people would open Task Manager and kill random processes they didn't understand. Best to make a little more effort to understand what the OS is doing before taking a scalpel to it. Or if you'd rather not, there's always OpenBSD (being serious here, it's pretty cool).

I understand the desire to disable Siri system-wide, but Spotlight? How else are you going to find your files?

I'm often annoyed how slow/unreliable Spotlight is, especially in Mail, but what's the alternative here?

It seems that one can't turn off the resource-hogging "knowledgeconstructiond" even in Sequioa.

Maybe Apple could offer a $200 upgrade on Mac purchase to get it without all of the Apple Intelligence features?

Went down this rabbit hole a few months ago seeing whether it was at all possible to disable the automatic OCR / processing of all image files on macOS.

Wasn't able to figure out how to do so but this blog was absolutely the best resource for digging one layer deeper on all things Spotlight-related, highly recommend.

This is becoming a more serious problem now Siri is going to be Google powered.

My org disables Siri on the work laptop, I’m new to having a mac at work, so not sure if it’s the norm

siriactionsd and siriknowledged power Shortcuts and Siri Suggestions. You will need to disable those features if you want to kill those daemons.

Honestly I have no idea if they have the best answer, but I thoroughly respect a blog post like this that is so concise/wastes no time. Here is the issue, here is what we want to do, here is what it won’t do, ultimately this is the best solution we have come up with + clear instructions.

A small but big detail that irritates me is one used to be able to search Applications faster through the dedicated Applications overlay, but now this behavior appears to just be a shortcut to Spotlight, which suffers from incredibly poor index planning.

In the past, when Spotlight was too slow to show me my most used applications by the first few letters, I'd bail and use Applications.

Now I'd have to use Finder, but opening that up would be slow enough that I'd almost need a desktop shortcut.

So, in essence, I have to hack around the most common functionality of using an application on an operating system, which is finding the damn thing. And this is supposed to be the most polished operating system on the market?

Apple frequently appears to be asleep at the wheel.