It doesn't seem to be very popular any more, but in the past it was really popular.
It seems like it isn't that popular any more, but a long time ago, it was.
こちらの言い方はいかがでしょうか。
英訳① It doesn't seem to be very popular any more, but in the past it was really popular.
It doesn't seem で「~ではないようだ」、any moreで「最近は、もはや」という意味です。
英訳② It seems like it isn't that popular any more, but a long time ago, it was.
It seems likeで「~のようだ」という意味です。not thatで「そうでもない」というニュアンスを表しています。
ご参考になりましたら幸いです。