It is not like grid is free. Grid costs a lot. Cables cost a lot. Transformers cost a lot. Transferring power incur in loss. Furthermore, if it is windy in Denmark, probably is windy also in Germany. While grid connections are indeed important, diversification of energy sources and storage are even better.
renewables are cheap, solar don’t work at night. Portugal has 37% hydro, 35% wind, 4% solar. Not all the countries have access to that much wind and hydro capacity. Italy is a stark example of a country with zero wind potential in the most industrialized areas (the padana plain). Having a big hydro potential is also great as hydropower is dispatchable. That means you do not need to build batteries to address the instability of renewable like wind. Renewable is great, but is not the universal solution. Each country and each grid need to work with what is given by nature to optimize the best for the use-case and level of consumption. Not all countries are lucky as Norway, Denmark, Ireland or Portugal. Italy is great for solar, but you said it yourself: solar do not work at night. So you either need nuclear or tons of batteries to decarbonize the grid.
As an owner of both an n150 minipc with 16gb of ram and an m1 8g air I can assure you this statement is false. The first is a toy compared to the latter. You can use it as inexpensive home server, but not as a work machine.