A year ago, they knew they could put money in at a $1 billion value because Softbank would do the $10 billion round and then they could dump it on retail. Even if it was a down-round from Softbank, who cared, they set the mark and everyone else felt like they got a bargain in the IPO. However, times have changed; who would still value a fake business at $1 billion if there was no hope of an IPO in the near future?
https://adventuresincapitalism.com/2020/02/18/is-pe-having-its-wework-moment/