The NRC isn't the bottleneck. For the recently completed Vogtle Unit 3 reactor, construction work and permitting work ran in tandem. Early construction work started in 2009 and all NRC approvals were completed by 2012. Neither NRC regulations nor lawsuits ever halted construction. Vogtle 3 was originally supposed to be ready in 2016. It suffered enormous cost overruns and delays due to the companies actually building it before finally entering service in 2023.
https://www.powermag.com/vogtle-3-reaches-initial-criticalit...
The identical AP1000 reactors under construction at VC Summer in South Carolina also suffered enormous cost overruns and delays, again not caused by the NRC or lawsuits. The construction problems were so severe at the VC Summer project that the project halted after spending over $9 billion, it led to the largest business failure in the history of South Carolina, and a couple of company executives went to prison for securities fraud:
https://en.wikipedia.org/wiki/Nukegate_scandal