Why is landing safely on the Moon so hard?

The M1 spacecraft, built by Tokyo-based company ispace, made a valiant bid to become the first private space vehicle to land on Moon. Instead, on 25 April, it became the latest in a long line of Moon missions that didn’t quite make it, apparently crashing on the lunar surface. Why is it so hard to touch down safely on the Moon? And when might the first private company succeed?

Only three entities have successfully soft-landed on the Moon…