They are. Here are the grids. https://en.wikipedia.org/wiki/Synchronous_grid_of_Continental_Europe https://en.wikipedia.org/wiki/Synchronous_grid_of_Continenta.

They are. Here are the grids. https://en.wikipedia.org/wiki/Synchronous_grid_of_Continental_Europe https://en.wikipedia.org/wiki/Synchronous_grid_of_Continenta... But there's only so much power you can transmit over the interconnects. If I read the list right, in 2019 Finland could generate 17.3 GW but only transfer 3.9 GW out of the country. Going further requires going through even more interconnects, which might have even lower capacity. There are long-term goals to increase capacity. There's also opposition to those increases.