A straight razor edge should last well over 7 shaves (assuming you do 3 passes). I don't see why a regular user would need to hone that often, assuming it does not want to have a fresh edge on purpose....
...If sharpness was not the problem, then what else could have caused this?
These are a few (perhaps rhetorical) questions, but maybe they will help you in finding what is the problem.
I think there's a lot of truth in all of this. I usually found that a blade lasted around 8 shaves before it needed to be touched up on the stones. That includes with some laps on CrOx after a few shaves to refresh the edge. Bear in mind that my dalliance with straights was in the days before diamond paste became popular, so when I say pastes I mean CrOx.
It was the same story when I sent some razors out to be professionaly honed. I could definitely feel the difference in the qualities of the edge, but it didn't last any longer.
I used to use a bevel setter and then a coticule. The goal was to take blades from bread-knifed blunt to HHT 4/5 and tree-topping arm hair. Whilst I didn't get it perfect every time, I could achieve this after stropping on canvas and leather, and get satisfactory shaves from a freshly honed blade.
Bear in mind, I really do like my blades sharp and fresh. I find lack of sharpness to be a significant cause of irritation for me, so I often do one-and-done for DE blades, and on AC blades I like to run them for somewhere between 4 and 6 shaves. I think I am probably a lot fussier than many people about switching out blades as soon as they become tuggy or uncomfortable, and this affected my perception of how long a SR edge was lasting.
Another thing I start to suspect is that my stropping technique was never where it needed to be, and perhaps my edges weren't lasting as a result of that. That's potentially a really important factor!
I kept my favourite straight and recently made some paddle strops with CrOx and FeOx then rehoned it. I was obviously out of practice, but managed to get to HHT 4/5. It still wasn't really sharp enough for comfort in the actual shave.
There's definitely an aesthetic and romance to using straights that appeal to me, but I can't deny that the ease of use and consistent sharpness of shavettes and barber razors seems to result in better shaves for me.