I wonder if this is incompetence, design, or both? Tariffs are nothing more than an inefficient, protectionist tax on the recipient state's people UNLESS your aim is to increase rent-seeking/favor-requesting behavior from industry in order to get them in your pocket politically. Then it's an inefficient, protectionist tax on the people, but a very efficient way to have increased political power for the regime. Who cares if everyone suffers? Public Choice Theory at its finest.
From what I've read - take that as you will, seasoned with as much salt as you like - it's incompetence. Donald Trump legitimately loves tariffs as a concept but does not understand how they work in reality - he's cited William McKinley as his favorite President because of his aggressive protectionist policies.
A cynical take is that it is design. The cost of the tariffs gets passed on to the people, but the refund goes to the corporations who have no legal responsibility to pass it back to the people. It's basically a $100B wealth transfer. It also primes people to accept higher costs. It's not like those prices went back down after the tariffs ended.