For some reason different Grammar books show a lot of examples of Future Perfect with such adverbs of time (by tomorrow, by next year, by 2050). It may give the impression that you only use such adverbs with the Future Perfect verbs.
"By tomorrow, he will have left Paris." Future Perfect.
BUT: "Tomorrow, he will leave Paris." Future Simple.
"By 2050, scientists will have found the cure for cancer." Future Perfect.
BUT: "In 2050, scientists will find the cure for cancer." Future Simple.
In the wild, I've come across examples such as:
"Do you think you can deliver it by tonight?" Present Simple.
"I will have a lot of money by tomorrow" Future Simple.
So what's the matter?
I'll even go so far as to ask: Is it grammatical to say "I will do my homework by tomorrow" or "I will leave Paris by tomorrow" instead of "I will have done my homework by tomorrow" or "I will have left Paris by tomorrow". If it is, what's the point of using Future Perfect with such adverbs of time?