On digital cameras and batteries.

I tend to be very reluctant when it comes to buying electronic gadgets. I always have the perception that I am spending money for something that is way more sophisticated than what I really need. Everything seems to have too many functions, so I feel like I am throwing away money for something that I don't need. Fact is that it's not very easy to find a cellphone that is only a cellphone, a TV decoder that is only a TV decoder, as everything has everything inside.
So after a few days of postponing I decided to go to a shop and buy a new digital camera. My old one is still functioning but has some condensation in the lenses, all pictures seem to be taken in conditions of severe fog.
I asked to the shop assistant for the most basic and cheap digital cam available to avoid the usual multifunction craziness. The shop assistant shows me a 70 euros model, way too sophisticated for me but it was ok if there was nothing more basic. When I was at the point of buying it, luckily I had the mental lucidity to ask about the batteries (I tend to choose everything on the same type of batteries, the old good AA, as it's easy to have always a few of them around and recharging them is very convenient).
The shop assistant proudly told me that there is a lithium rechargeable battery inside, so I don't need to worry about changing and recharging the AAs.
WHAT?
I don't have to worry... are you telling me that a lithium battery lasts forever?
No, it does not. It needs to be recharged, obviously.
But now, what's the point of having an internal battery that can be recharged using a USB connector instead of a couple of AA batteries? AA batteries can be recharged exactly like the internal lithium ones, plus you can keep a pack of them with you in case your lithium internal futility dies.
Know what? The shop assistant showed me a model running on AA batteries, but it had a lot more functions that I will never use and it costed almost 100 euros more than the cheap one.
I decided to buy it anyways.
Sometimes to have the basic you have to spend more.
What a crazy world.