Samsung is a much more widespread company. Samsung makes hundreds of different phones per year, and has different phone series such as the A-series, S series, Note series, and J series. Samsung has room to innovate. With its wide range of phones, Samsung can make new designs for their phones. However, Apple only makes 3 phones per year. This means that they stick to being safe with the phone design to give users a very reliable experience. Samsung has the ability to ‘wing it’ with their phones because there are no users dependant on one of 3 phones per year, they have a large choice of what phone they want to use.
It’s no surprise that Samsung is leading on this. Samsung does this kind of thing all the time: they produce 20-something new smartphones in a year, and they’re always looking for the next big thing. Sometimes those ideas — the Galaxy Zoom for example — go nowhere. Others, like the Galaxy Note, become an industry fixture.
The other reason is that Samsung is a display company, and they’ve been making flexible OLED panels for half a decade or more. That’s not getting anyone all the way to a folding phone, but it’s a necessary component.
Apple, on the other hand, doesn’t make displays (though you can bet they’re thinking about it, as that’s one of the most expensive parts of the phone they don’t make in-house). So Apple has no direct control over display technology. They have the money to buy anything that can be bought… in fact, they bought a company that makes power efficient micro-LEDs, so they may some day be a display company. But not yet.
Second thing is that Apple only releases 2–3 phones per year, and they don’t generally take risks. They’re happy to let Samsung, Huawei, Lenovo, Xiaomi, BBK, etc. show them a dozen ways how not to make a folding phone. Apple waited on fingerprint readers, eye unlocks, larger screens, larger camera chips, more cameras, wireless charging, larger batteries, no button, all-screen, etc… pretty much any innovation over the last decade. They weren’t first.
But when they did jump, they pretty much did it right. Sometimes better than it had even been done. Making a good idea great is Apple’s only remaining superpower. And the folding phone, right now, is kind of the worst great idea ever, because the idea itself is very cool, but the implementations are terrible. And expensive! I’m not willing to pay $1,000 for a new phone, much less $2,000+ for one that’s not likely to survive a few years of regular use.
Apple has never been one to be the first to do something. Apple prefers to wait until a feature has become mainstream before swooping in and creating the best version of that product. So we will see a foldable Apple Smartphone, just not anytime soon. Although, Apple might be thinking about it. They have filed patents. They’re just not ready with a product. And unlike Samsung, the whole not-being-ready thing kept them from releasing a product.