I don't use High Gloss paper unless the image is, for example a polished car that has a shiny appearance. In my opinion printing on glossy paper downgrades many good images.
When you look around at Landscapes, Gardens, People, Buildings, Animals, and so on, colours may be rich and vibrant, but not shiny Gloss. Matt paper is superb for images that have a wide dynamic range of contrast and colour and presents you with an artistic finish.
Images versus Prints - When you view an image on a back-lit screen, the luminance level is the same for every shot. In comparison a print can be Gloss down to a non-reflective Matt finish with varying textures. The photo will be improved by selecting the correct grade of paper.
A quality print is one where the colours are not over-saturated, has a subject of detail, and is interesting to the viewer.
What is a professional photo? -
One that is good enough to be placed in a magazine, or a photograph that people are prepared to buy.