But Colombia also has a digital nomad visa. Why did they create it if it was having a negative effect on the country?

Also, in my country, London is absolutely filled with immigrants/expats who create a shortage of housing for native brits and increase prices. They also lower wages for locals. That includes poorer immigrants, as well as Russian billionaires buying up real estate. That's why my own capital city has become too expensive for me to live in. But I suppose I'm not allowed to complain about that.

It's up to governments in each country to control the borders in a way that benefits the country the most. If the high number of foreigners in Barcelona are causing a problem, the Spanish government needs to make visa restrictions stricter.

It's not up to individual digital nomads to cut themselves off from geoarbitrage opportunities. It's up to governments to control borders in a way that benefits the people of the country. A managed influx of digital nomads can be a benefit to any country, which is why digital nomad visas are popping up all over the world.