I'll save you all the aggravation, it'll never happen, eventually there will be something else, another must have knife, one that finally checks all the boxes, really tickles your fancy, your EDC Grail, (can there be such a thing? I think not) I've been collectin', accumulatin' and usin' knives of all Kings for nearly 50 years now. Half a century of discoverin', learnin' about and enjoyin' everything about knives, includin' most of the people involved in the industry and community.
I can assure you that you can never stop lookin' for the one so where do you go from here? You share and discuss what you've learned with others, you find other things, nuances you never knew or understood about a pattern or a particular Stella or alloy. Even if you found the one(s) you'll ever need there's always room to learn more and share and discuss that with others.
Just look at how far the industry has come in terms of materials and production methods not to mention the skill and art of the knife and how we adorn them in the last 25 or so years.
Even the last 15 years with companies like ZT
You haven't even begun to test the custom waters. If you can afford a Sebenza you can start checkin' out custom/handmade fixed blades and basic slipjoints. There is a lot of talent yet to reach it's peak around here and some that is at it's zenith.
Then there's the historical knives, patterns that have proven themselves throughout time, Buck, Schrade, Queen.
You ask where to from here? The answer is anywhere you want because if after a half a century of knives I still haven't found the one or ones. I come close but in the end I believe you're like most enthusiasts/users and as long as the science of metallurgy keeps advancing and you're still usin' and lookin' for the best, you're not done so back to work.
I carry a Plain Jane Sebenza 25 right now along with a Love Wolf/Loveless City Knife paired with a 2015 CSC Serpentine Shadow Jack with Birdseye pivots and bocote scales in a leather pocket sheath along with the JD Ellis Lanny's Clip in the opposing LF pocket with the AO ZT 0770CF.
As long as you're alive you'll keep learnin' and lookin'. Like I said somewhere earlier once before, you never stop learnin'.