is it possible for the debris [of the Long March core stage] to hit earth's surface and possibly cause considerable damage to inhabited areas?
Yes. Not only is it possible, but it has actually happened just two days ago.
More precisely, it depends on exactly which Long March variant you are talking about. There are 10 different series of the Long March family with a total of 22 different variants. Only one of these 22 variants routinely enters uncontrolled: the Long March 5B, which is a variant specifically designed for the sole purpose of launching modules to the Chinese Space Station that has no second stage and instead mounts the station modules directly onto the first stage. This first stage is massive and has no facilities for a controlled de-orbit burn.
On July, 24th 2022, China launched a Long March 5B with the third major module of the Chinese Space Station. The first stage reentered on July, 31st 2022, with debris landing on the island of Borneo.
A similar thing happened with the launch of the first module, where debris crashed in Cote d'Ivoir on May, 12th 2020.
In both cases, the debris missed houses or villages by only a couple 100m.
It's common for Spacex to de-orbit the second stage over the ocean (since they still have fuel for controlled re-entry).
That doesn't always work, however. A COPV from a second stage that failed its de-orbit burn crashed into a farm in Washington in March 2021. The major difference between this and the Long March 5B is of course that this was an unplanned failure whereas with the Long March 5B it is the normal plan.
However, just last month, pieces of the Crew Dragon trunk section from the Crew-1 launch crashed on a farm in Australia, and the Dragon trunk is indeed not planned to be de-orbited safely but reenter uncontrolled.