The B777X will probably be the new Jumbo jet when it eventually gets into service, it will replace the B747/A380 with a twin engine modern aircraft having lower running costs. Pushing the entry into service date back a few years would give Boeing time to address all its issues and present a safe, thoroughly checked aircraft to its customers when the travel market recovers in 2024.
At that time it would be a decent option for airlines looking to replace their A340/A380s and B747s which were grounded during COVID and may not be worth bringing back given the expense of operating quad jets with a limited life remaining.