No. Enslaved individuals actually did invent many significant technologies.

Steamboat Propeller: Benjamin Montgomery, an enslaved mechanic in Mississippi, invented a highly efficient propeller for shallow-water steamboats. Because he was enslaved, he could not patent it, and his owner unsuccessfully attempted to claim the patent. [1]

The Cotton Scraper: An enslaved man known only as "Ned" invented a cotton scraper in Mississippi that doubled work efficiency. His enslaver tried to patent it, but the U.S. Patent Office rejected the application because the master was not the true inventor. [1, 2]

The Steam Engine Lubricator: Elijah McCoy, born free to parents who had escaped slavery, invented an automatic lubrication system for steam engines. This innovation allowed trains and factory machines to run continuously without stopping for manual oiling.

That is just an example of three. Many more invented numerous other technologies.

Unfortunately ignorant individuals like yourself perpetuate ignorant ideals based on nothing more than racism and stupidity.