[Moto G5 Plus Questions & Answers] mindmajick:
2GB of RAM is just dandy for any smartphone application. Even games.

There are a few reasons you find more memory on phones; some good, some not-so-much.

RAM is Cheap. Really cheap these days. In the days of 32-bit CPUs, there was no practical value to offering more than 3GB RAM, like my Samsung Note Pro 12.2 tablet here. But with 64-bit processors, 4GB is a few bucks more than 2GB. Naturally, manufacturers don’t want you to know this. After all, even if it’s $2.00 a phone, if you’re Apple, that’s $200 million extra profit in a year.

Marketing Wars. Consumers are a simple people.. they don’t really know how stuff works. So basic numbers sell. A 4GB phone just sounds like twice as much as a 2GB phone. A 20Mpixel camera sounds so much better than a 12Mpixel camera — even though the top phone cameras right now are 12Mpixel cameras (the iPhone 7 is also a 12Mpixel camera, but not on the top, its sensor is too small).

Multitasking. The rule of thumb for Windows, at least, used to be 2GB per CPU core. Which means my PC here ought to have at least 12GB. I have 64GB… no problem. But if you extend this to Smartphones, pretty much no one has 2GB per core (and yeah, there are 8 core Smartphone chips, but most of those are big.LITTLE designs, they only normally use four cores at once). Neither Android nor iOS are as memory-hungry as Windows, and we’re not running a full Photoshop or Altium (my EE CAD software) or AutoPano Giga (the reason I have 64GB on my desktop). A typical Android application can ask for up to 48MB of RAM, no more. But there’s a special way to ask for hundreds of MB of RAM (considered impolite), and native apps can make Linux calls and get all they want. And you can actually have them all runinng at the same time. So if you’re a power user, you may want more than 2GB. But it’s not one app, it’s having a faster system with everything running.

High Density Screens. When I had a smartphone with 256MB RAM, I also had a 640x480 screen. My LG V10 today has 4GB RAM, but it’s also got a 2560x1600 screen. So does a 13x increase in screen resolution need a 16x increase in memory? Not exactly. On Android, your apps have to deal with all kinds of different phones, and most apps don’t need to directly interface with allocating screen bitmaps or anything, any more than a web browser does. But iOS is based on pixels and bitmaps, and also, there were very few models. So every software compamy knew exactly what resource they had. Then the iPhone 6 Plus came out, with the same 1GB as all sorts of other Apple phones. Only, the screen was 1920x1080 resolution. And all screen drawing was actually done in 1242 2208x1242 and then downscaled to 1920x1080. Bottom line: the overhead too enough extra memory over any other 1GB iPhone that some things just broke. Which is why they put 2GB into the iPhone 7.

So if you’re an iPhone user, your only choice is 2GB today in a new model. That’s exactly the right amount, since the memory size will drive software development. And you don’t have the option for more, anyway. For Android, 2GB is a good amount for 2017. I’m not really convinced I need more than that. Then again, I haven’t used up half of the 64GB internal flash on my V10, and the 256GB microSD card is mostly full of photos and music. Not critical, but nice to have.