> Replaceable batteries are kind of a lost cause these days.

But, this is the signature open and hacker-friendly phone! Sure removable batteries have fallen out of style in the mainstream, but this isn't a mainstream product.

But I'm in their target market and I don't want a replaceable battery. I just want the battery to be serviceable when it wear.

For a given phone size, a replaceable battery require some additional space which means it will be smaller than a non-replaceable one.

I don't want to buy one or two additional battery to carry with me when I can get a battery that last a bit longer and that I can charge with any power bank. (mine or the one of a friend as there is no compatibility problems)

Users who want replaceable battery are niche in the niche.

I highly doubt this phone is going to win the thinness wars anyway, so the space savings aren't going to be as relevant. It would be much smarter to differentiate themselves on features such as replaceable batteries, which the mainstream market has ignored precisely because they want to chase thinness.

The real question is, how many users want replaceable batteries, and is there enough overlap between that group and the audience for an OSS phone. I would imagine the overlap is significant, but without market research on the subject I don't know if I'm right.

But you still want to sell it. And more so, you want to please the majority. Oherwise you might be killing the product by picking a niche.

You're just as likely to kill the product by not targeting the niche. Trying to please the majority puts you in competition with the big players. This phone's specs, with the possible exception of the CPU/GPU (haven't looked into it), are a downgrade from the 6 year old Note 3. The only saving grace at the moment is GNU/Linux, separated baseband, and hardware kill switches. Is that going to be enough? If the battery removal tools aren't as simple as a screwdriver, it's already lost me.

I think the thickness is just a minor factor, but there are two major reasons why they are out of style:

1. Making the phone water and dust resistant is much easier without replaceable batteries

2. The manufacturers want to sell smartphones and replaceable batteries are probably the single feature which extends the lifetime of a smartphone the most

The first reason alone would be good enough for many consumers to give up on replaceable batteries but combined with the second reason we come to the situation we are currently in.