It's also the OG kimchi as Koreans didn't have red peppers until the Columbian Exchange (but have been preserving vegetable via brines since the Three Kingdoms era)!
If you can't eat normal kimchi due to spiciness, there are variants of kimchi that aren't spicy and resemble sauerkraut or doesn't even include cabbage at all.
I might be ignorant but for me the flavour of kimchi is far more complex and varied - sauerkraut is pretty much always the same.