The fig tree is a symbol, Judaism. The tree was really there and really not bearing any fruit. But it was full of showy limbs and leaves!
Some people ask why Jesus would have expected the tree to have fruit in the spring, at the time of the Passover, when the usual crop is in the fall. This is because some varieties develop a crop in the spring on the last year's growth. they are called "breba" figs (click here).
How could the tree appear to be killed overnight? In my studies on it a few years ago, this passage came up (I've lost the link):
"Fig trees are prone to attack by nematodes (especially Meloidogyne spp.) and, in the tropics, have been traditionally planted close to a wall or building so that the roots can go underneath and escape damage. A heavy mulch will serve equally well. Today, control is possible with proper application of nematicides. In India, a stem-borer, Batocera rufomaculata, feeds on the branches and may kill the tree. Lepidopterous pests in Venezuela include the fig borer, Azochis gripusalis, the larvae of which feed on the new growth, tunnel down through the trees to the roots and kill the tree. Another, called cachudo de la higuera, has prominently horned larvae up to 3 1/8 in (8 cm) long that can destroy a fig tree in a few days. There are also coleopterous insects of the genera Epitrix and Colaspis that perforate and severely damage the leaves and shoots. Scale insects include Asterolecanium sp. which attacks the bark of trees weakened by excessive humidity or prolonged drought, and the lesser enemy, Saissetia haemispherica."
(Check out Mt. 3:10; Lk. 3:0) The narrative need not necessarily be of a supernatural event, but one in which Jesus, not finding "breba" fruits, recognized rapidly developing irreversible disease or insects killing the tree, and seeint tht it was done for, pronounced it dead, never to bear again. This could have a similar parallel of a human in his sinful condition, or in a nation of humans, so far advanced that deadly damage to ones life and spiritual productivity could not be undone.
Just an observation for you on the fig tree experience (Mt. 21:19-21; Mk. 13:11, 20-21).