Air heat pump electricity price increased as of January 1, 2022

I was referring to the switch to low temperature at that point.

Me too. With the facade, windows replaced, and radiator or roof insulated additionally, nothing else remains but low temperature heating. The building envelope then has KfW40 efficiency, only possibly the basement does not.
And of course, "just like that," a heat pump is connected = low temperature with 30 degrees flow temperature. This works very quickly and easily in the multi-family house sector. It doesn’t require much effort, "only" money.

There are plenty of approaches. Local heating networks, especially low-temperature networks + booster heat pumps, are a promising model. But even there, cities and municipalities have to loosen their purse strings. If you look at the heat pump electricity like that, it’s obviously a scattergun approach. Still, I don’t understand why the better-off always have to/be supposed to get the short end of the stick. If someone contributes to the climate goals and invests, they shouldn’t also be "punished."

Nevertheless, I don't understand why those with higher incomes always have to/should be the ones to miss out.

It's not about "against higher earners." With all targeted support measures, I also fall through the cracks even though I am not a higher earner. It's about the basic principle.
Subsidies must be collected and managed beforehand. Every euro less in subsidies saves more than one euro. Currently, we create incredible bureaucracy just to move money in circles. Take, for example, the great energy allowance...the state pays the employer money so that they pay me 300€, of which I then have to give back almost half in the tax return. Yay!
On the other hand, every subsidy is always a misincentive. With enough subsidies and punitive taxes, you can even make ox carts competitive again; it's all a question of political will. But objectively, that's not sensible. If anyone thinks I'm exaggerating...battery-powered airplanes are not far from this example.
And then, a subsidy does not solve the actual problem. Instead of tampering at the end of the chain and subsidizing electricity for heat pumps, we should start at the beginning of the chain and ensure that electricity can be produced cheaply in this country. This includes relaxing monument protection and the possibility to properly pass on energy renovations to tenants (we used to have this...but the costs were too high for tenants and some tenant advocates now prefer to spend expensive money on gas...). Then the houses will renovate themselves and switch to heat pumps all on their own.

Would, would, craft scissors ;)
Germany, Europe, and the whole world simply slept through this entire issue and deliberately ignored it.
Now we're all paying the price for it.
Clearly, it makes sense to tackle the problem right at the beginning of the supply chain, that is with cheap, renewable electricity.
However, there simply isn’t enough time left to not heat the planet by more than 1.5K.

I keep hearing from scientists that about 20 years ago there was no mobile network and no cell phones, etc., and that the energy transition would also be possible if we worked just as quickly here as was done with mobile communications.
What they forget is that it was something completely new, and no citizen had to reach into their pocket to finance it.
With the energy transition, two-thirds of existing households are affected, who have to invest, and that in the mid five-figure range.
How do you want to get them to cooperate?
If it doesn’t pay off during their lifetime, it’s pointless. That’s simply the way of thinking.
With the investment sums involved, you could spend what feels like 20 winters in Thailand for the same amount of money...

Don’t get me wrong, I see it the same way you do. But given the lack of time, there are only limited options left. Unfortunately...

I also received mail from ENBW today, consumption price from 18.48 cents to 30.30 cents and basic price from 9.89 euros to 10.29 euros. :-(

I keep hearing from scientists that about 20 years ago there was no mobile network and no cell phones etc., and that the energy transition would also succeed if we worked here just as quickly as with mobile communications.

Perhaps the difference is that this was not a planned economy project organized by politicians but a private-sector one. The botched energy transition is now, of course, a drag on the heat transition and similarly in transport. Instead of continuing to rely on piecemeal bans, subsidies, and sector targets, simply cut bureaucracy at the front of the process and make fossil fuels gradually less attractive at the back through emissions trading. The question of how to implement this concretely on-site can be very well solved by the private sector and the population themselves. The high investment sums for private individuals could possibly be cushioned through somewhat subsidized loans. Ultimately, the investment in renovating the house is also countered by an increase in value, so it is worthwhile even for the 70-year-old retired couple if you calculate honestly and do not just take the rent-free property as a given.