The Sun is the ultimate energy source for our planet. We need it for warmth and photosynthesis (and lots of other stuff.) Life would definitely not exist as we

The Sun is the ultimate energy source for our planet. We need it for warmth and photosynthesis (and lots of other stuff.) Life would definitely not exist as we know it without either of those. Eg: without photosynthesis, bacteria would quickly (on a geologic scale) consume/turn to waste anything valuable (including oxygen). Without warmth, or planet would be too cold to sustain life. We get our oxygen mostly from photosynthesis as well as a few other smaller sources (methane based, I think.) Turns out, seasons help much of life on Earth too which is just defined by the tilt angle as it processes around the Sun. Additionally, stars are factories for creating heavier elements. We wouldn’t have many of the requisite elements for life on Earth without them having been produced by the Sun first. Plants (or more generally, photosynthetic life) are the most direct consumer of solar energy and thus the most abundant source of energy for other living organisms on the planet.