I understand your fear and I'm having a bit of the same worries.
The Netherlands is quite the opposite of Australia. It is a country with one of the highest densities in the world and unfortunately it keeps increasing.
Since 1990, the population of the Netherlands has grown from approximately 14.9 million to about 17.8 million in 2023. That's almost 20%. I think in 2025 we are already over 20%
The total area of the Netherlands is 41,543 square kilometers. If you divide that by the number of people, everyone would have 'only' 233 square meters.
There is a shortage of houses. People are getting older and stay in their homes. Especially here in the western part of the Netherlands cities and towns grow towards each other. Houses are being built where there were meadows and open areas.
The birth ratio has been declining a bit over the years and the baby boomer generation is getting old, but on the other hand immigration increases.
I'm trying not to be a pessimist, and I love the Netherlands a lot, so I won't leave anytime soon, but things aren't getting any better.
I should remember what Europe is like and perhaps that would make me get some perspective! It was hard to find space on your own there. Like you, I TRY to not get pessimistic but sometimes I'm glad I'm at this stage of my life - I don't want to die for at least 20 years but I'm not not ill want to see what happens in 30. Gosh that sounds terrible doesn't it? Really I need to work harder on my perspective.