I agree that "less is better" with chemical fertilizer until you know that your soil is too "lean".
"Everyone says" that the only way to know what your soil needs is to get a soil test. But a lot of people never bother. They add compost until the soil "feels good" and only add a little chemical fertilizer iof crops seem yellwoish or grow slowly ... and then respond well to a little fertilizer, like they "green up" and grow faster. You can fertilize one small patch of each crop to see if that helped. Nitrogen is probably the thing most often deficient, but it also is the most toxic thing when added in excess.
Too little fertilizer might slow their growth down a little, or turn some leaves a little yellow.
Too much fertilizer can kill or damage the plants rather severely. Leaves curl and "burn", root hairs die or lose their beneficial root-fungi. If the soil becomes saline, the plants may even become unable to take up enough water and die promptly.
Less is better, with chemical fertilizer. If you can see at a glance that your soil is just AWFUL, like sandy and NO organic content and nothing grew well there before, not even weeds, you might consider light chemical fertilization as the lesser of two evils.
But adding organic matter - even a lot of mulch and compost - is almost always safe and beneficial. The only downside is that adding mulch on top of the soil takes years to break down and add organic matter. Sheet composting on top of the soil might only take months, but it adds organic matter slowly, too.
Adding compost ("finished" compost, decomposed compost) is almost an instant improvement in tilth, water retention, and soil structure (aeration and drainage). It also liberates mineral nutrients (the only thing that chemical fertilizers CAN add), but gradually. That is safe for the plant, and it delivers nutrients the way they are "used to" in nature: slowly as microbes digst the compost and release its minerals.
Also, humic acids are produced and released in that process. They slowly dissolve and make soluble the surfaces of rock grains, releasing mineral nutrients very slowly.
(Sometimes someone might add a whole LOT of semi-composted manure all at once, like a 4-6 inch layer, before rains have had time to leach out excessive salt, which some manure might have. Where I live, worrying about saline compost is pretty funny: you would have to build a roof to keep the rain off, to allow salts to build up. But I hear that too much "salty manure" can be an issue in dry climates or desalinized soil.)
Compost never burned any roots! Adding a 2-3 inch layer or more of finished compost (if you can get your hands on that much), and turning it under the top 12" of soil and mixing, will improve almost any unimproved soil. Then add another 1-2 inches once or twice per year, even if you don't till it under. If you can't get or make enough finished compost, you can "sheet compost" or mulch with things that break down quickly. That adds organic matter too, but more slowly.
The organic matter in compost and mulch feeds the soil life (fungi, bacteria, insects, worms, grubs, and many others).
Symbiotic or helpful soil life maintains the soil structure and releases minerals and interacts with root hairs in supportive ways. Many soil organisms destroy or inhibit plant pathogens. Root hairs secrete things analogous to hormones that signal and attract some microorganisms, and repel or inhibit others.
I think that plants, soil and soil organisms all co-evolved over many millions of years, maybe more than a billion years, to promote more soil life and more plants.
