Originally scheduled to launch in 2007, then pushed to 2011, then 2014, then 2018, then 2021, then late 2021... It was originally conceived in the mid-1990s as a $500 million telescope. Later, the cost ballooned to $9.7 billion, and that's just NASA's share. The European Space Agency is also spending €700 million, and the Canadian Space Agency is spending CA$200 million.

"Like a transformer in the movies, about 50 deployments need to occur after launch to set up the huge system. With 344 so-called single point failures – individual steps that have to work for the mission to be a success – this deployment after launch will keep us on edge for 3 weeks or so. For comparison, this exceeds single point failures for landing on Mars by a factor of 3, and that landing lasted only 7 minutes."

There is currently no way to repair it if it fails. It looks like a mission designed to fail. There's an awful lot of reasons to not be optimistic about success. Maybe start developing a servicing mission now?

http://www.parabolicarc.com/2021/12/06/james-webb-space-telescope-fueled-for-launch/

https://manyworlds.space/2021/08/05/the-many-ways-the-james-webb-space-telescope-could-fail/