Right, but Finland shouldn't be the benchmark for solar power viability. The total population of places with a climate similar to Finland's is quite small compared to areas where solar is viable.
On the other hand, places where local solar is particularly viable (like Sahara) shouldn't be a benchmark for off-the-grid solar viability either, because not that many people live there. In practise, you really do need to have grid and storage to use solar.
(Local off-the grid solar is somewhat usable even here, but it does need battery storage. It is popular in holiday homes that are not located close to power lines. E.g. I have a cabin which is a kilometre away from nearest electric lines; building a power line to the grid would cost in the order of 50 k€ while an off-the-grid solar-powered system runs electronics and a fridge with an investment in 5k€ range.)
Exactly. Maybe Germany would be a reasonable benchmark, if one factors out the subsidies (which used to be very attractive, I'm not sure about the current status). There are lots of rooftop solar installations in my area (southwest).