What year do you think will be The Sims 4 last year before its no longer being developed for? Sims 1 2000-2003 Sims 2 2004-2008 Sims 3 2009-2013 Sims 4 2014-20??
I think 2020. That leaves 2-3 more major EPs (one per year) plus whatever GPs and SPs they come up with. I don't think many of our computers could support more packs than that anyway.