Lisbon: 6,452/km2
Barcelona: 16,000/km2
NYC: 25,000+/km2 (depends on the source)
Lower East Side NYC: 33,600/km2 - due to zoning regs, there are very few buildings over 9 stories... but every building is 9 stories!
Lower East Side NYC 1910: 144,000+/km2 - visit https://www.tenement.org/ to learn more.
Kowloon Walled City, 1970s: ~2M/km2 !!! - inspiring 1000s of dystopian Sci Fi stories from Akira to Blade Runner. https://www.google.com/search?q=Kowloon+Walled+City
25,000/km2
It’s pretty quiet too! :)
There are other decent metropolises in Portugal and other fun spots around the country not to get crammed in the capital.
People can work from nearby towns where housing costs are relatively moderate and just hit the head office in Lisbon one or two times a week.
Corporations and people need to adapt to the changing circumstances and to be open to make the necessary adjustments to advance in this world.
This is the exact way that janitors and baristas and everyone servicing those 100k+ a year software engineers is priced out.
Took a train to Sintra, there were endless and endless 6 story-miles long buildings forever. Portugal seems insanely dense.
Lisbon: 100.05 km^2 , 544k people
San Francisco: 121.48 km^2, 873k people
20% more room than Lisbon, 60% more people.
What? Have you ever been in Lisbon? The city is pretty dense as it is. You could mostly just build higher, and that has its limits too, depending on the structure and foundation.
Adding more housing outside the core of the city might not be attractive enough. And increasing the density of people also means you need to increase the density of services (public and private) and utilities, which also comes with its own problem.