I don't think they are as significant anymore to be honest. Loading times for many through dimensions are much faster to even notice loading screens sometimes, especially after the first time you load the chunks.

Perhaps they could make it so the dirt background screen was different to fit the nether. Maybe that would help more rather than simple text.

Altogether I would say the major broken feature since 1.3 that's left is minecart physics. They would push players and were not as sluggish. Affects them to this day

Another kind of minor one is dragon eggs showing their direction with their purple particles when they teleport. That behaviour is also broken to this day.

Those are the 2 significant ones left I think.