This was originally a discussion on the Fairphone subreddit, where users almost unanimously responded with that they were fine with if a future Fairphone did not have a toolless removable battery as long as the battery was still easily replacable with minor disassembly. One of the main reasons being that modern devices generally have plenty of battery life on a single charge.
I remember carrying an extra battery to switch out when the first one died being a somewhat standard part of using feature phones, because their battery lives were terrible and chargers in public places weren't really a thing yet. It was so common that some feature phones used to come with two batteries in the box and you could buy standalone battery chargers. Damn, I just realized: the golden age of feature phones is now over a decade ago.
What do you think? In terms of the niche of highly repairable devices, how important is a tool-less, instantly replaceable battery to you? Compared to if you had to unscrew the back panel or the screen assembly to access the battery. Would a laptop or a tablet with a toolless battery be more important to you than a phone, since those tend to have shorter battery life and be harder to find public charging spots for?
I guess another issue is barrier to replacement? Technologically inclined people will not find taking out a couple screws or removing a non-glued display assembly very difficult at all, but for the layman, even that could be a daunting task, possibly leading to more devices being thrown out because of dead batteries instead of being repaired? Though, this also seems more a problem with how society views repairing devices than a fault of the design itself.
Tool-less is important for generic consumer hardware. Ideally, you would say it should be toolless for all consumer hardware, but a laptop computer explains us why that is not a good idea for a mobile, mission critical device. Smartphones are handled even more carelessly, since they are hand sized devices, and their connectivity utility is mission critical.
Laptops and mobiles probably should not be toolless, but rely either on the mechanical latches or screws or a simple glue like T-3000 or T-7000. The current system, as far as devices themselves go, is not too horrible. There are exceptions like Apple, newest Pixel 6 series and so on, but midrange phones are decently repairable. Same goes for ThinkPads, but there are a lot of problematic practices among other laptop makers, especially Apple. What is bad is the unconditional availability of either company genuine batteries or good third party batteries.