Today's global world map still has space for more empires to emerge ( Based on historical data )

The peak of the UK share of world GDP was in 1870 at around 24.28%.

During the existence of the UK/ British empire, other empires on the world map were ( 1900 data ):

The Russian empire

The second French colonial empire

The Spanish Empire

The empire of Japan

Second Portuguese empire

( Others )

Today, The US, the replacement of the British Empire, controls 25% of world GDP.

China can be said to have replaced the Russian empire.

The EU acting as the replacement for the French Colonial empire.

Brazil can be considered the replacement of the second Portuguese empire.

This leaves out replacements that haven't filled in the vacuum for the Spanish empire and the Empire of Japan, with the closest replacement being ASEAN which is only an economic union with no teeth in any other sphere.

The world altogether is too large for the current number of empire equivalents to be able to control all of it, which leaves out a vacuum that still needs filling.

One can expect the emergence of a new major player or the expansion of Brazil in South America, alongside the rise of two empires proper in Africa, one empire in central Asia, and one empire in the middle east.

This is due to the existence of power vacuums in these territories, with none of the other empires able to exert complete influence in these territories, leaving them free to reintegrate into new systems of governance.

We can expect these empires to rise to fill in the power vacuums in these territories within the century, with Saudi Arabia in the middle east, and Kazakhstan or Mongolia in central Asia.

Just like how China arose as a new player on the board in the 21st century, and India is expected to rise quite a way far up in the coming decades, there are more players that will rise up in their regions and dominate as well, due to the natural accumulation of wealth towards the top in stable human territorial systems.

The empires of the previous century only broke down due to competition from other empires. In stable systems key players naturally arise over time. The lions could not reach all the way to India, so the Tigers emerged there as the apex predator. The same principle applies.

All nation states are evolving into a competition between regional nation states with one dominating. The next step after regional dominance becomes one for global hegemony.

Today, the nation state that is rising up to be the dominant player in its territory is Brazil in South America ( It's share of South America's GDP is continually on the rise ) and India ( Whose share of South Asia's GDP is more than 80%), similarly China is close to reaching the 80%+ mark for its share of GDP in East Asia which would make it the dominant regional player, and EU almost at the cusp of crossing 80% of the GDP share of Europe.

Once these territories completely dominate their regions, the only way forward left for them is to compete with other major regional players from around the world.

That is, territorial/ influence expansion.

We can see this with the ever eastwards expansion of the EU. The global trade expansion of China and India, and the resurgence of the Brazilian economy and influence over South America.

Conclusion:

The world is moving towards developing multiple manifest destiny nation states moving on the path of cultural conflicts with one another over time resulting in the expansion and collapse of empires similar to what occurred during WW1 and WW2.

American culture, vs European culture, vs Chinese culture, vs Indian culture, vs South American culture.