Paint on an Ohio house does not fail evenly. Walk around your own place and you'll find the south and west elevations are always a season or two ahead of the north side, because that's where the sun sits all afternoon and where the wind drives the rain. If you only ever look at the front of the house, you're grading the easiest test.
The first honest sign is chalking. Rub a dark cloth across the siding; if it comes away powdered with color, the binder in the coating has broken down and the surface is no longer sealing anything. Chalking is not an emergency, but it is the clock starting.
The next signs are the ones that cost money if you wait. Caulk joints that have opened at the trim, corners, and window returns are letting water behind the siding, and water behind siding does not stop at the paint. Bare wood showing through on fascia, window sills, and door casings will start absorbing moisture, and rotted trim is a carpentry bill, not a painting bill.
Peeling tells you something specific depending on how it looks. Paint peeling in sheets down to bare wood usually means moisture got underneath, from an open joint, a failed gutter, or a ventilation problem inside. Paint peeling between coats, where you can see an older color underneath, usually means the last job went on over a dirty or chalky surface. Both need the cause fixed before the repaint, or the new coat fails the same way.
How long a good exterior lasts here depends far more on prep than on the price of the paint. A house that gets washed, scraped, sanded, spot-primed, and properly re-caulked will hold for years. The same house, same paint, applied straight over chalk and open joints, will look tired by the second or third winter. That gap is the entire argument for reading the prep line on your estimate.
If you're seeing chalking and open caulk joints now, the right move is to get it looked at before the freeze-thaw cycle works on those joints all winter. We'll come out, walk the whole house including the side you never look at, and tell you honestly whether it's this year's job or next year's.