I've definitely seen gas boiler/heater in city center apartment, Olomouc, Czech Republic.
I am from Ukraine. While in theory district heating is awesome there are some problems in implementation:
* every summer there is a three weeks period without hot water, a lot of people have electric boiler as backup, it is even bigger than gas boiler
* no hot water in off peak time on upper floors of old buildings, have to flush some away, fixed with loop in new buildings
* old buildings vertical heating pipes makes it impossible to bill apartment, no incentives for heat insulation (wall and windows) or reducing temperature, 25°C in winter is a norm, fixed with per apartment pipes in new buildings
* a lot of heat escapes pipes, melted snow patches in winter
* fixing broken pipe is messy, change of the pipes even worse, seen both
* requires high level of participation - at least some small towns have no district water for 20 years, some even without district heating
* modern gas boilers are 90+% efficient [1]
Some new buildings have heating plants, looks like a better idea. But heating is a big part of CO₂ emissions, stored hydrogen heating plant is a future. Even better if it is a power plant too.
[1] https://www.theheatinghub.co.uk/boiler-efficiency-guide-and-...