Moss acts as a ‘green mulch’. It will help to slow the drying out of soil and create a good growing environment for other plants. It does not damage other plants or trees. It also stays green through the winter. While it goes dormant when the soil is too dry to sustain it, it will immediately ‘green up’ again when misted. Since it only grows on the surface, it does not require water saturation, but only surface watering. It also has a disproportionately high beneficial contribution to the environment, compared to other plants and ground covers, in both carbon and ecosystem impact. It requires less maintenance than other types of lawn, and grows best where other types of lawns struggle most. It also can be planted to beautify or add interest to other plants and objects in a landscape, including wood, cement, stone, and live trees.

Mosses are not by themselves bad, but they may indicate more acid soils, which may not be appropriate for some other plants, flowers or small bushes. It might be beneficial to do a pH test of your soil and figure out what would be appropriate for what you are wanting to grow…

Perhaps it takes away water from other plants, for example, if I’d plant some flowers or small bushes? And that’s where it’s bad for the garden

I don’t see why you couldn’t use algae/green moss in your garden. I am not sure how it might affect the pH of your soil. You may want to do a pH test afterwards. Coconut fiber or Coir is generally recommended as a substitute for Peat Moss, which has traditionally been mined from ancient peat bogs…

Jerry, moss is just another part of the ecosystem. Some people may consider it a weed, if it is growing where they do not want it. But as far as I am concerned it can be a beautiful part of a landscape!