Some of the handy Excel functions (like XLOOKUP, LET, LAMBDA) are only available in the newer versions. Sure, they aren't universally used because of the inertia, but in my opinion useful enough to justify the upgrade.
You're right wrt. those new Excel functions, but I consider this to be an unusual exception - these all happened recently, so even if you want to upgrade for them now, you'd still be fine not upgrading for over a decade before :).