Libson is a global city, easy air access to pretty much everywhere in europe/us/asia, good international schools, low cost of living, and very importantly, very mild, california-like weather. Once you have kids, you need access to good international schools so that they can integrate back into US public schools/colleges without getting left behind academically. Also you have access to a lot more culture and night life than out in the country. For young people the dating pool in large cities is very deep. Getting out of Libson/Porto as an expat, dating can be difficult if you're not a fluent speaker of the local language, and Portuguese is wildly different from Spanish when spoken, even though they look similar on paper.

That's where job opportunities are, and that's why more housing will increase the opportunities, and then the price of housing...

For a post-Covid world where remote job opportunities are on the rise, this is becoming less and less of a pressing matter.

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.

Not all people can work remotely!

This is the exact way that janitors and baristas and everyone servicing those 100k+ a year software engineers is priced out.

Remote work is certainly a way to de-focus big metropolis, a bit.

Usually for work-related reasons.