If you're not larping hard as a "bikepacker" - at which point, who cares anyway, carry as much as you can - all you need is a decently sized saddlebag.
I have a small one from ali that can fit 2 tubes, multitool, and a rolled up drawstring backpack. So, worst case scenario, I'll just pull over to a gas station and buy a snickers bar or a couple of bananas.
These storage bags that fit in the triangle are good but at the same time suck because now reaching to the bottle is worse, handlebar bags are a aero joke and usually can't fit much anyway, all while not being less practical than the framebag. Top-tube bags could be as good as the framebags if they don't hit your balls when you dismount, which is the case in many standard geometry frames.
Why do you need more storage anyway? Phone and keys can go to your saddle bag or a hip pack/small transversal bag if you don't like jerseys, but they're honestly a godsend. It's the best storage a cyclist could want IMHO.