Good Morning,
A few months ago, I thought the same thing, and bought an Asus PG27UCDM (4K240 27" OLED). It was a disaster.
The problem is, these OLED screens are meant for media playback in a darkened room. Their pitch black and peak brightness shines in a dark room. However, their average brightness is very low. OLEDs can be bright in tiny areas, but can’t extend that brightness to the whole screen. By default, the screen dynamically adjusted brightness, so if you moved a white window onto the screen, the rest of the screen dimmed. That may be fine for movies and games, but was obviously terrible for desktop work. You can disable this, but that limits brightness to 200-or-so nits, which is not bright at all. No problem in a dark room, but not bright enough for an ergonomically lit office.
Furthermore, the screen (like many OLEDs) has a non-standard color matrix, which gives text a fuzzy, multicolored shimmering outline. You can disable such subpixel font rendering on an OS level, but there are always some apps who do it anyways.
Finally, the screen comes with various burn-in prevention methods, which dim and periodically shift static screen elements. I found it hugely distracting to have my task bar and menu bar shift around periodically, even if only by a few pixels.
And that beautiful black point? In my bright office, it was masked by ambient glare anyways. The colors were nice and accurate, though.
I sent it back. For all my hopes of buying an “apex screen”, this one was uniquely mismatched with my requirements. I replaced it with an Asus ProArt PA27UCGE (4K160 27" IPS), with hardware calibration. Since this is built for graphics work in a lit environment, it comes with tremendously good anti glare coatings that actually resulted in a much darker black point than the OLED. And the hardware calibration is surprisingly useful, too, since it applies to all apps, not just color-managed ones. I have since bought a second one, because it just works well.