People don't stop wanting things.

Total GDP can keep rising so long as technologist can improve efficiency through robotics, inventions and scientific breakthroughs.

GDP just describes peoples amount of activity. People will always build bigger buildings or monuments (see egypt pyramids, dubai skyscrapers, cambodia angkor wat). These are actaully not inelastic as megaprojects will quickly hit real limits regardless of the amount of capital. (I can always add 10 more floors to the tallest skyscraper, or 10 feet to the longest wall, or 10 facets to the most ornate church)

There has never once in history been a point where people decieded that they where going to stop innovating or producing permanently. This is equivalent with death.

So the people with the most money at some point will decide to build things which they spend all their money on which increases GDP.

Also the actual "number" of gdp if heavily controlled by USA inflation rates. So we should always look at gdp in regards to inflation adjusted dollars to get a clearer picture.

You would just think there has got to be end to it all... technology needing to increase so much, indefinitely, the imagination falters tbh. Its like we have to become space gods by year 2500 or we are going to go bankrupt as species anyway.