I think there’s a lot more historical anecdotal evidence for Bigfoot than for ‘aliens’.
That depends on your sphere of research. One could say the same in reverse since there are hieroglyphs/drawings of flying objects that date far back into the Hindu traditions, Egyptians and Chinese cultures.
If you believe in Bigfoot but not aliens you will be predisposed to believe your statement. If you believe in Bigfoot and Aliens, you might be conflicted as to how far back either goes.
There is anecdotal evidence, big hair guy meme aside, that evidence for both reach back into the ancient cultures. The fact is they both remain a mystery and depending on one’s subjective beliefs determines how one will fall in this debate.
And there are some stories that conflate ‘UFO’ activity WITH Bigfoot.
I’m not sure that all those ‘flying machines’ in ancient drawings and paintings actually refer to ‘flying saucers’. We’d need someone versed in historical symbology/semiotics to help enlighten us on that.
The fact that we ‘see’ something in the work of ancient people doesn’t mean that we are ‘seeing’ what they actually MEANT.