Yes, I am pretty sure this is the case. It’s not hard to think that people that walk / cycle past a business will notice more things.
But only if they are local enough to be there by bike from the start. If anyone of you thinks that people ride their bikes 30, 40, 50km to the next city to do shopping, you might be in for a surprise. Those shops that would die without a car park are those who draw their crowd from outside the cities, too. And no, public transport is no option either for people from outside the city where there only is a morning bus and an evening bus.