It seems like you already know why it's not realistic. Fossil fuels fulfill the role of a marginal power source very well, neither renewables nor nuclear can replace that role as of yet. There are still plenty of issues that need to be solved towards electrification, lets not make it unrealistically difficult for ourselves.
It is however not a policy I would advocate or vote for. I rather oppose fossil fuels especially when they are being subsidized through taxes. Europe can also not really handle an other winter, especially if the weather would not be exceptional mild. Bailouts can only be paid so many times before it becomes unrealistic.
This winter and perhaps the one after that as well will be interesting for sure, after that the major natural gas risk should be mitigated by having enough LNG terminals and supply. There is still quite a bit of leeway to reduce taxes on electricity, but when you're short on supply you might not want to incentivize electricity use.
Trying to disincentivize electricity use during periods of low supply do not work. Governments feel forced to step in if factories has to shut down or people can't heat their homes. Those not willing gets voted out, as was also demonstrated this winter.
All this is a local maximum where every action is rational but the result is terrible for everyone involved. Paying through taxes does not actually make the energy price low, and the massive cost to the environment will have to be paid at some point in the future.
More LNG terminals and more fossil fuel plants will not make the situation better. Demand through electrification is growing faster than the economic savings from using even more fossil fuels, and when winter comes the same scenario as last will occur. The only ones who will profit is those countries that export fossil fuels.
There is also a huge loss of public trust when green party politicians are advocating to keep subsidizing fossil fuel plants. If environmentalist want to keep oil and natural gas plants, then how will the public be convinced of climate change? The strategy need to be clear and fossil fuel free, and if that solution is wind, solar and storage then that plan need to be up front and part of the budget discussions. It should not be the argument from environmentalists that we should be using natural gas because it happen to be cheaper that nuclear.