I consider the possibility of prehistoric advanced civilizations a real possibility. Rising oceans and earth and climate changes tend to obfuscate the evidence.
Most modern scholars are not even looking. One of my favorite examples is the archaeology site of Göbekli Tepe. It dates as far back as 11,000 years ago; it is a massive megalithic site. Scholars say it took hunter gatherers at least a millennium to construct the site.
OK... What did they use as site plans? How did they keep records of construction parameters? How did so many people hunt and gather while exercising skilled labor duties? If it is a religious site, were there religious records? How were food supplies provided for so many workers by hunter gatherers {they had to constantly move to provide for their families}?
These sorts of questions can be multiplied. Scholars just make acceptable proclamations without any thought to practical considerations to meet their theories.
Look at the megalithic site of Macchu Picchu - supposedly built by the Inca whose 'Empire' lasted about 100 years - along with a huge empire of roads and central administration and cities and temples. The timeline does not necessarily fit the great achievements of a society without the wheel or a written language.
...just saying 🤨
Reading list, if you are interested:
America Before - Graham Hancock
Magicians of the Gods - Graham Hancock
Before Atlantis - Frank Joseph
Denisovan Origins - Andrew Collins/Greg Little
Gods of Eden - Andrew Collins
Above are pretty much a collection of hard to find information with very little to no author inspection of sites, relics or monuments; Hancock does some personal investigation.
For more recent history try:
The Crystal Sun - Robert Temple
Egyptian Dawn - Robert Temple
The Sphinx Mystery - Robert Temple
Netherworld - Robert Temple
Temple does his own original research at various sites and museums with his wife who takes many many photos; he includes many translations of academic research not found elsewhere, as well as historical photos. He has not publish in over 10 years and may have passed, but his web sites are still up.