It definitely does if your neighbor decides they need extra money and jacks up the rates and/or doesn’t like you anymore and shuts it off. Then it is whoever has the most self contained power wins.

I don't think the scenario you describe is a realistic scenario within the European energy market. Prices are decided by supply and demand and the market is getting more interconnected so single points of failure become less likely.

I do wonder what happens in case there is no wind and no sun all over Europe and the demand is higher than the supply. It's probably very unlikely to happen but then countries will prioritize their own citizens (as we saw now during the covid crisis) and then we could have blackouts. I assume scenario's like these have been researched but I don't follow this subject, maybe someone else here knows?

While true, that feels about as likely as Bavarian independence.

Russia has done it with natural gas in the last 10 years. The UK seemed like a great EU partner - until they weren’t.

Things change and over the span of 10-20 years, things can change dramatically. The life span of many of these decisions is 30 years or more.

Which is why I gave the example of a regional independence movement rather than saying it’s impossible.