Nearly a tie: Algeria and Democratic Republic of the Congo differ by barely -1%% in area — about 2,322,788 km² km² against 2,334,703 km² km².
Both sit in Africa, so this is a same-region comparison: the new Equal Earth map draws both with the same honest geometry, and the real gap is exactly the 1× you see above.
The old map muddied it further: Mercator inflates Algeria about 1.3× and Democratic Republic of the Congo about 1×, so on a Mercator-style map this pair appears 1.3× apart instead of the true 1×.
Democratic Republic of the Congo fits 0× into Algeria.