You have to keep in mind that that removable battery has disappeared from devices for a reason: it’s inefficient. Even having a case around it and providing the connector and latch means you’re making the battery smaller and the device bigger.

That said, I do feel like there’s a reasonable middle ground to be had: not a swappable battery, but a very easily replaceable one. No special hex screws, etc. Sure you can’t carry around six of them, but if you can replace it once a year you probably won’t need to... and you can always carry a power bank with you instead to recharge it on the go.

I think the SD card requirement is short sighted. As often as storage (and cables, not to mention other things) change I think the added space requirements in something like a phone, even for something as small as an SD card (plus the adapter and the spring mechanism, housing, etc.) is a waste. In a decade you may not be able to even find the same kind of storage anymore. Even if you can it’s not like the latest game that rings in at a bazillion gigathings that would so totally easily fit on your new SD card is actually going to run on your 9.5 year old phone - the processor, memory, etc. simply wont be up to the job.

I guess the SD card thing depends on your requirements, but I like carrying my music library with me and a few movies, so I don't mind if the volume of my phone is a few cubic millimeters more.

I would be fine with an easily replaceable battery though... but again, I don't mind a little more volume.

Speaking of SD cards, phones really should begin implementing support for UHS-II and UHS-III MicroSD cards since right now the transfer speeds are lagging behind that of internal UFS storage