Battery life is an area that may be difficult for smaller phone makers to compete on. I think Apple especially puts a ton of engineering effort and coordination into making iOS and their apps work efficiently with their hardware, reducing complexity, runtime cycles, and power consumption as much as possible, on top of already highly-efficient ARM hardware.
Over years of doing that (kaizen), the result is optimized hardware/software fusion with industry-leading battery life. But it seems like it takes a non-trivial amount of additional engineering time and effort to accomplish this, that will be difficult to match by smaller mobile tech startups.
I hope the open source community around Librem and Pine will be able to replicate that effort, but I'm not sure this kind of consistent incremental upgrade work is attractive enough to volunteer FOSS developers. And being maximally effective at it most certainly requires the parent company to coordinate the effort across hardware, software, internal teams, and external volunteers.
Although Motorola smartphones have been pretty solid for a while now, so not discounting that there has probably been a lot of R&D effort invested on their end too.
My Nokia was getting 8 days before I started putting all the apps on it. The more apps I added, the worse it got.
Nowadays I generally restrict apps from running anything in the background/sync'ing etc etc if I can.
I am happy to wait a few seconds for email to sync when I open the app rather than have my phone beep at me for every new email...
It's actually the opposite - most modern (especially flagship) phones don't really last more than a day (and here day isn't even 24 hours, but more like 16 hours). It was a massive deal when Apple finally increased the battery life of their iPhones with iPhone 13 series so it can outlast a day of normal use.
There's some difference in mid-range market though - since people buying cheaper phones tend to value battery life, you can get mid-range Android phones with downright massive batteries. Especially in Asia.