Last year I was convinced I'd go back to Plus size at the first opportunity, but I've come around to a smaller phone in the meantime. Suits me better, I never watch video (bar the odd clip) on it, and I've deliberately been using my phone less anyway, a habit that goes back to pre X days. Battery life was my fear last year coming from the Plus to X, but I aways have 40% or so left by the evening these days.
The one thing I'll be envious of though is better Face ID, if it happens. Not in general usage, works better than fine for that, but it is a pain when I'm waking up horizontal and it barely recognises me. Seems to have improved at that lately though, works most of the time.
I'm not upgrading for just better Face ID though. There may be an as yet undisclosed improvement that tempts me, but I doubt it, it's been diminishing returns on phones across the board for years now anyway.
I will be upgrading my SS Series 2 Watch though, ooooh yes.
.....and a maxed out new iPad Pro, whenever that is coming.
So Apple will still see a chunk of my wallet, ha.