They head a break in the 2000s and it took them a few years to come back with their album that has songs like Venus and This Love. After this they went on another break after releasing an MV in 2015 and they came back on 2018 for 1 MV and since this they did nothing else wich means they did not released stuff since almost 3 years now ... so they cannot be the group thats around for the longest cause if that would be the fact than they wouldn't be in breaks so much and so long and cause they are on breaks so much most newer KPop-fans don't even know they exist
You can call them a legend as much you want but most people simply never heard of them and probably won't call them as a long living group by how long their damn breaks are