Notepad ++ has had this since 2003
Welcome to the party Microsoft and definitely a compelling reason to upgrade to Windows 11
(the fact that this is actually news is sad beyond words)
You can sigh and shrug, and I understand where you're coming from. But the truth is Microsoft did fairly crappy included applets intentionally. Apols for the digression. Skip the rest if tl;dr.
There's a history to why Notepad and other included Win applets & "toolkins" remained so basic and functionally minimalist for so long. Internally it was part of a very intentional strategy to help entrench Windows back in the days when that was far from accomplished.
That's sounds counter-intuitive, I understand. But it really made sense in historical context. How do I know? I was there in Microsoft, and had this exact discussion many, many times at "Corp" in Redmond.
Back then the greatest imperative was to establish and entrench Windows on the desktop. Billg, Steveb and most others understood clearly that people don't buy PCs to run operating systems - they buy them to run apps in order to accomplish real things that OSs don't. Without a very large number of apps the Win ecosystem would eventually shrivel. So, internally, the real focus was on driving 3rd party Win app development by seducing as many ISDs & ISVs (independent software developers & vendors) as possible to develop and keep developing for Windows. The thinking was that 3rd party apps and tools in dozens of vertical, local and broad markets would help drive broad Windows adoption, which would encourage more ISVs to target the platform with their apps, which in turn made the whole ecosystem attractive. Recursively, like an ever-upward tornado.
So, this thinking resulted in a very specific intention to NOT to add enhanced functionality into the shipped-free-with-Windows applets like Notepad. This would create obvious space for independent developers to come up with their own "enhanced" apps so they can make money with their apps and therefore stick with Windows app development. This helped grow the Windows apps base (later called 'ecosystem') which was critical to entrenching Windows as the preferred platform. Internally, execs were pleased when better notepads, tools and utilities appeared from third parties - it all drove Windows adoption and gained mindspace in the very people who played a critical role in enabling the adoption of PCs+Windows, ie developers.
The boomers here will perhaps remember steveb's "Developers! Developers! Developers!" dance at an internal company meeting in the latter 90s (I was there, in the front row), which went viral once YouTube got going eight or nine years later. That was one of his ways of hammering home the mantra internally: Love Developers because a massive cadre of independent developers create the apps that drive PC adoption that drives Windows adoption that results in entrenchment of Msft APIs that in the end produce the revenues and profits that the company requires. Microsoft then believed to its core that its success depended on making external people successful and rich -- incl ISVs and channel (dealers, distis, SPs, prof svcs, etc) -- because that was the only way it could have the global reach to drive the volumes needed to makes oodles of boodle.
It's one of the beauties of capitalism that informed self-interest incentivises the enablement of success in others (customers, partners, etc), because that's the best way to reach bigger markets and eventually make more money. No-one can be all things to all people, so best is stick to the knitting (what you do best) and leave space for others to do what they do best.
Every time I fire up the crappy but basically functional Notepad in Windows I remember this. I don't need more, not even a tabbed Notepad. But those who do have a choice of dozens of better ascii text editors more suited to their specialist needs. No one app no matter how rich can meet everybody's needs and preferences, so best is encourage as wide range of choices as possible. And it's mostly due to the intentional plan of not including a richly functional Notepad in Windows, even if the original reason is no longer that applicable in a changed world.