How to deal with increasing property tax burden?

What is that supposed to be, an obligation to accept an exchange? If a suitable one-room apartment is available in the same district for Grandma Erna, she is obliged to swap her three-room apartment with a young couple?

Honecker jumps for joy. Why don't we just allocate the apartments by the state right away? And the professions too?
The automobile industry is also doing badly, perhaps all German car manufacturers should be merged into a combine?

But I have to warn you. Your fancy new single-family house in the countryside with 150, 200 sqm... they will then be confiscated and given to party-loyal functionaries. The average citizen does not need a single-family house...

I would argue (though I cannot prove it) that it is primarily the landlords who ultimately do not agree to the exchange or would demand a new rental price from the new tenant. No one disputes that there are many reasons among tenants not to exchange, but if two willing parties have found each other, why should it then fail because of the landlord's greed? That could be solved so easily. So even if it only works for 1% (which would still be almost 90,000 people; 10.5% live in too small apartments), why should it be reduced to zero?

Are you trolling? You know exactly that it’s about the landlords (as already wrote) and you paint the bogeyman of the socialist planned economy dictatorship on the wall here, which wants to harass and oppress every single citizen and especially poor old grandmas. Pure strawman argument. The issue is precisely about balancing the power relations between those with influence and wealth (=power) and those without. To protect individual citizens against the arbitrariness of corporations and, yes, also public institutions.

What is this supposed to be, an obligation to accept a swap? If an adequate 1-room apartment is available in the same district for Grandma Erna, is she obliged to swap her 3-room apartment with a young couple?

I'll explain it to you slowly again:
Housing company X has 400 apartments. 1, 2, 3 and 4-room apartments.
Grandma Erna has lived in a 4-room apartment for 50 years, would like only 2 rooms. But with a new rental she would have to pay more rent than now for the 4 rooms. So she leaves it.
Family A lives with 2 kids in 2 rooms, same company.
Now we oblige the company to offer a swap exchange and to agree to a swap between Erna and Family A, whereby the rents must necessarily stay the same as before.
No disadvantage for anyone, only advantages.

:
Take a look at residential areas like Waldstadt or Stern in Potsdam, in Berlin the Märkische Viertel or Gropiusstadt. One company owns hundreds of apartments there, and on every street there are all apartment sizes.

And there, the 75 sqm apartment also costs less than the 120 sqm apartment, at least so far. Only with new rentals is a significant increase applied, and that is where the whole thing fails.

As a landlord, I would be more interested in increasing the rent of the larger apartment by a higher percentage than that of the smaller one. So Grandma clears out 120 sqm for 600€, moves into 75 sqm for 400€, and the big place is newly rented for 1,600€.

By the way, when I look at the sums currently being considered for our dilapidated infrastructure and incapacitated Bundeswehr, the rising property tax is probably only the beginning.

By the way, a surcharge must be added for new rentals because the old contracts are often completely ruinous. You can only get such low prices for completely unrenovated old buildings or post-war buildings anyway.
For many landlords or their buildings, energy renovations are pending, which can only be financed if the rent is raised significantly.

You are all so convinced of the heat pump and WDVS. Then you also have to face the consequences and accept the high rent. The 300, 400,000 EUR for renovating a 10-unit old building do not fall into the landlord's lap, and he also wants to make some profit with the property. If renting is not worthwhile, no one will do it anymore. You can see this in the housing shortage.

PS:
And anyone who already sets 3,000 EUR/m² as a minimum for a single-family house should not be surprised if a new apartment can no longer be economically produced for less than 15-20 EUR/m² cold rent.

(...) Now we oblige the company to offer an exchange platform and to agree to an exchange between Erna and family A, whereby the rents must necessarily remain the same as before. (...)

When you change jobs, do you also take the same salary as before? Or do you ask for more?