Why didnt the ancient plants get decomposed by microorganisms to form humus but instead stayed fresh enough to get compressed - Science - Coal and Petroleum

Question

Why didnt the ancient plants get decomposed by microorganisms to
form humus but instead stayed fresh enough to get compressed to
form coal?(with relation to carbonisation process)

Anita Dahiya · Accepted Answer

Coal is not nothing but fossilized plants and dead and decaying
matter Every organic material is attacked by microorganisms Even
fossilized plants were broken down which later lead to the
formation of coal

Why didnt the ancient plants get decomposed by microorganisms to form humus but instead stayed fresh enough to get compressed to form coal?(with relation to carbonisation process)