But it technically was hugely popular at some point.
Cuz technically any game that are simply old but were popular at some point could now qualify.
It was never hugely popular. It got some critical acclaim due to its art style and approach to gameplay, and a few small bursts of sales here and there with price reductions and the Steam and HD releases. The fourth game sold something like a million units across combined platforms. I think that, between multiple re-releases and price cuts, the first game might have made it to 2 million units sold since 2008. It certainly never did as well as Final Fantasy Tactics or Fire Emblem post-Awakening.