Re: That probably explains..
removable back, which as I recall would regularly break on most phone models leading to your battery ending up on the floor.
Yes, until about 10 months ago I had a phone with a replaceable battery under a flimsy-looking thin plastic back. The phone fell quite a few times, the plastic, and sometimes the battery, separated from the rest of the phone and ended up on the floor, but never broke. Putting the battery and the plastic back into their proper places resulted in perfectly working phone in 100% of the cases.
replacement service (which only takes an hour in store)
You don't value an hour of your time very highly, do you? The advantage of that flimsy easily separable plastic back was that walking into any odd mobile phone shop wherever you happen to be in the street, swapping the battery, paying (only for the battery, no labour) by cash or card, and walking out of the shop with a perfectly working phone took all of a couple of minutes. That's as opposed to a special trip to a lab or service center + "1 hour" + paying for the technician doing his job.