not all compost is created equal.
and if you are using it for fruit trees, you would want a compost heavy in carbon(browns) and less of the greens.
the difference is referred to as "bacterially dominant" or "fungal dominant"
fungi are better at breaking down woody material, and bacteria, the greener stuff + food scraps etc...
that said you will have some of both in all compost.
and one of the main benefits of compost, is not just the NPK and micro-nutes
but, also the micro-organisms....
the fungi, bacteria, and the larger things that eat them like amoeba , protozoa, nematodes, etc...
and larger things yet that eat them... arthropods, earthworms etc...
so the best thing about compost is it can provide "missing" micro-organisms
(protozoa for example) to "fix" the part of the food-web that is not working right.
all those guys eat and poo.
they excrete large amounts of waste -called a "waste stream" ...
in live healthy soil, this is enough to feed most plants
my "guess" is that some plants, hybridized by humans, produce so much fruit, and grow so fast
that the demand is hard to fill, but even then, i think good compost and live soil should be enough.
also
each one of these micro-organisms HAS to have enough boron, zinc and other micro-nutes to live.
so its hard to have a deficiency with live healthy soil
i do infuse my compost with fish emulsion and molasses
and try to add as diverse a set of plants as i can.
this creates a diverse set of bacteria and fungi
lots of research has been done on this in recent years.
this website is by one of the top scientists.
http://www.soilfoodweb.com/She has lots of videos too
https://www.youtube.com/results?search_query=Elaine+Inghamone on compost
https://www.youtube.com/watch?v=fnXsw5EzuM8