Intel was able to do 5 nodes in 4 years because the lead fab has the mission to lead, seed and the seeds transfer to another fab. It used to be every other year a new node, before all the difficulty starting in the 2010 until present. The Ronler Acres Moore Park complex is a grand scale. There is probably a cheaper way to do R&D but that is the Intel way. It worked better when fab lite wasn't a viable option as it is now.
On the topic of taking fab lite off the table for Intel, so they focus on the old tick tock, now that Intel's capital structure is different, with Trump and SoftBank and Nvidia, perhaps they can sack the board members who still want to see fab lite happen? Make a statement that fab lite is dead?