Pentile typical omits subpixels to achieve the resolution, so yes if you have an LCD and an AMOLED with the exact same resolution and the AMOLED is pentile, it won't be as sharp because it has literally fewer subpixels. But that's rapidly outpaced by modern pentile AMOLEDs just having a pixel density that vastly exceeds nearly any LCD anymore (at least on mobile).

There's RGB subpixel AMOLEDs as well (such as on the Nintendo Switch OLED) even though they aren't necessarily RGB strip. As in, just because it's not RGB strip doesn't mean it's pentile. There are other arrangements. Those other arrangements being for example the ones complained about on current desktop OLED monitors like the one in the article. It's not pentile causing problems since it's not pentile at all.