I would guess OP meant "integrated into" rather than acquired by, so that they are available by default rather than having to be installed separately.

Parts of them were integrated. Take a look at the Win XP Task Manager and at the Win 10 one.

They are still way behind ProcExp for example.

A straightforward tool for everyone is not "behind" a comprehensive tool for experts just because it does less. Minimizing the probability of someone using Task Manager to shoot themselves in the foot is probably more challenging than adding an advanced feature to ProcExp.

The "Details" tab on the current task manager is plenty for shooting yourself in the foot but it lacks features for power users. I personally think they just don't care.

Unfortunately, ProcExp started breaking with Windows 10 (columns regularly got into a broken state, requiring reset of the registry settings), plus they ruined the color scheme for the tray icons, so I switched to Process Hacker instead.

Mark went work for MS, as I recall. This was some years ago; I don't know about currently.

MS sucked in the tools/pages onto its domain. Navigation to/of their pages and versions became somewhat shittier (per the... "canonical" MS web experience, I guess). I seem to recall a bit of public pushback on this point, and things improved somewhat. Maybe I mis-recollect; I've been mostly away from Windows for quite a number of years, now.

He's CTO of Azure and therefore a VIP at Microsoft...

In his spare time he's also managed to write three novels.

But there's also https://live.sysinternals.com/ as usual.

I think the former developer of process monitor and process explorer is now CTO of azure if memory serves me correctly.

And for some (stupid?) reason they weren't integrated into the OS so a lot of people don't know about them.

If they're integrated into the OS they have to be supported at the same level as the rest of the OS, which entails the same rigorous processes w.r.t. updates, bug fixes, etc...

By keeping them out-of-band, that support requirement doesn't apply, allowing the tools to be much more aggressively updated and released without the same degree of oversight. There's a reason they're licensed separately and effectively with no support or warranty. Doing so enables their rapid development without/less-of the usual bureaucracy.

I can confirm, I downloaded the suite from Microsoft a few weeks ago.

Still comes in handy to track down some specific types of bugs.

I really hope they someday integrate the tools into Windows considering how few megabytes they take up

I really hope they don't, because then their releases would be intertwined. Instead of getting the latest and greatest sysinternals tools all the time, I'd probably have to wait until the next Windows release.

That is not how it works these days, a lot of things can update separately from Windows itself, my current solution is to use Scoop an open source Windows CLI package manager which can update it whenever a new version comes out

they were