Okay, I understand (what many others don't) that although the S20+ is listed as a 3X-30X zoom, the actual optical zoom is 1.08 so the focal length of the actual lens is basically the same as the non-zoom camera. This is unlike say the S10 5G which the actual lens of the camera is 2X. However Samsung makes up for this by using a 64MP sensor. This basically results in as good or better zoom shots up to about 5X zoom than a phone with a tele-camera with a 2X or 3X optical zoom lens but only a 12MP or 16MP sensor.
This is a bit astonishing considering the number of pixels decreased by the zoom factor squared when using digital zoom. So, the lowest zoom of the tele lens on the S20+ at 3X is essentially a 7MP sensor. 3 squared is 9. 64MP divided by 9 is 7.1MP. Compared to say the S10 5G which has a 2X optical zoom and 12MP sensor. So a 3X zoom for the S10 5G is a 1.5X digital zoom of the 2X optical. 1.5 squared = 2.25. 12MP/2.25 = 5.3MP. So you can see how the S20+ can keep up with other cameras with 2X or 3X optical zoom but only 12MP sensors. It's notable though that with 2X zoom, a camera with a 12MP sensor and a 2X optical zoom has a higher resolution image than the S20+ at 2X zoom since the S20+ doesn't have an optical zoom lens.
What's more interesting is the 64MP sensor on the S20+ has a 0.8um pixel pitch which means the sensor is roughly 9,500 pixels by 7,150. So at 3X zoom the sensor output is going to be digitally cropped to around 3,160 x 2,380. However no matter what zoom resolution you use, Samsung outputs a 4032x3024 size image, basically "faking" the resolution for all images taken at anything over 1X zoom. The file size goes down as the zoom goes up even though the image resolution stays at 4032x3024 because the JPEG compression algorithm basically can see it's a fake resolution (essentially a lower resolution source image interpolated up to a higher resolution.)
I'm not sure why manufacturers do this except for only from a customer satisfaction perspective as people would be complaining why their 10X zoom images are only 950 x 715 pixels. Yes, S20+ users, that is roughly the true resolution of a 10X zoom image from your phone. But consider on a 12MP sensor with 1X optical lens, that true cropped resolution is closer to 400x300!
The bottom line is the S20+ Tele Camera is basically equivalent in resolution to a phone with a 12MP camera with a 2.5X optical zoom because it's not actually an optical zoom lens. So Samsung's advertising it as a 3X "hybrid optic zoom" isn't a total lie, but 2.5x would be closer to accurate as far as the equivalent of an optical zoom on a 12MP sensor.
In reviewing tests images, to get the best images on this camera you just want to use one of the 3 cameras without manually zooming in. If you do zoom in on the tele camera, try to not go above 5X.
The FE actually has a telephoto camera as good as the plus because it's an actual 3X optical lens but with an 8MP sensor. Reviews with test shots have shown the FE takes a little better zoom photos than the plus. However the FE is lacking in many other specs compared to the Plus but for the price the FE in my opinion offers a better value for what you get in the camera capabilities than the Plus. The Ultra has the best cameras, slightly better than the Plus but at a higher cost, larger size and heavier phone.