Maybe there were advanced human civilizations on the planet before the current (there are such theories), but at some point they also got so advanced that they

Maybe there were advanced human civilizations on the planet before the current (there are such theories), but at some point they also got so advanced that they accidentally/systematically removed all of their traces, and have declined in some way. (though the theories are have better explanation for their lack of artifacts apart from a few OOPARTs) Our age unfortunately will have long-lasting traces in the forms of various plastics and forever-chemicals.