The M1 Carbine was considered successful in its day because it was new technology. Semi-auto longarms were still somewhat experimental.
Thus, their standards for reliability were different than todays. Then it was felt the pros outweighed the cons and they considered the trade-off worthwhile. Today, if the M1 Carbine was introduced, with all of its inherent issues, it would be a massive failure.
It's a cool piece of history and I enjoy mine for that reason. But, as a practical weapon in the here and now? Absolutely not.