You see figure collectiong for me is like end game in an MMORPG. It is possible to reac it and be satisfied with it, but it will keep increasing. Let's say level 60 was considered end game a year ago. A year later new content arrived and level cap was raised with new gears to get.
Same thing applies to my figure collecting. Even if I suddenly had the money to buy every figure off my wishlist, as long as companies are coming out with more and more new releases, chances are I'm goint to want some from them (the figma wishlist is only getting bigger with LLENN and Emilia etc..).
There is also another way: Discovering older series, realising there are figures of them, thus wanting figures that were alredy released eons ago, but suddenly having a need for them (looking at you Touhou).
In the end, there will be always something to get as long as the figure industry continues being this giant market.