The BM-30 Smerch remains a fearsome weapon. It’s often compared and not unreasonably to the M270 MLRS on the opposite side of the Berlin Wall. But in many ways, it’s like the last generation of propeller aircraft, while the MLRS was one of the first jets. And I’m not talking about guided rounds.
One of the biggest differences is that the Smerch has to be manually reloaded one rocket at a time. The MLRS/HIMARS just involves plopping in a new canister full of rounds (and the launch vehicle itself has a crane to boot). Many other newer systems (primarily Chinese, Israeli, and Turkish) also use the canister system, even if some still need the extra expense and risk of a separate loading vehicle.
Though too little and late for the current war, the Russians did eventually go for the box MRL with the Tornado series. However, I’m earnestly baffled why they didn’t try to do so more while the USSR was still intact, given the obvious advantages of such a system. Sunk costs of existing rockets and later post-1991 financial troubles are a possibility. Or maybe it was because the Smerch’s giant rockets couldn’t be canisterized. But still, given the prominence of artillery, and the use of other mechanical aids (automated naval vessels, autoloaders for tanks), it still is a little surprising.