Stronger in munitions? One western artillery shell is worth countless Qassam rockets. The Qassam rockets are largely useless from a military perspective because you aren't going to hit anything with them.
This is an apples and oranges type comparison, except Hamas is stuck with crabapples.
Qassam rockets are not "useless." They've killed multiple people, including kids. They are relatively low-yield compared to later Grad/Fajr/M-75 type rockets Hamas used, but to say they're "useless" is a huge overstatement, and the implication that they represented Hamas's entire arsenal is wrong.
The reality is that Hamas also had dozens if not hundreds of R-160 / M-302 medium range rockets (up to 200km) and long range Ayyash 250 rocekts (travel more than 200km).
In addition to the direct devastation the rockets cause, they also force large swaths of the Israeli population into bomb shelters, which has other military benefits for Hamas. It was part of the 10/7 strategy they employed.
People like to pretend Hamas was a tiny force. The reality is what I said: it was larger than many European militaries, with an arsenal to match.