Because if there was it would repudiate the following verse :
Exodus 20:11 ~ For in six days the LORD made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the LORD blessed the sabbath day, and hallowed it.
You can’t pick and choose the Bible verse you believe or don’t believe.
Those who believe the Gap Theory repudiate the fact that God created the heaven and earth, sea and all that is in them in six literal days.
Since the earth is almost 6000 years old, it makes me wonder how scientists come to the conclusion that some things date back as far as a million years, is it any wonder the Apostle Paul said :
1 Timothy 6:20 ~ O Timothy, keep that which is committed to thy trust, avoiding profane and vain babblings, and oppositions of science falsely so called: