Is there a specific app or feature that is keeping others "iPhone bound"?
Yes. Actually, there are.
1. There is no equivalence to Airdrop anywhere in the entire world. The closest anyone can get is some form of pseudo FTP server between the phone and its target (another phone, a computer, etc...). But never something as seamless and integrated as Airdrop. In fact, the closest alternative to Airdrop is Dukto, which has ceased development for years but is still usable today.
2. Accessories: search for iPhone accessories, you get probably millions of results on and offline. Walk into any random phone accessory shop and you'll see accessories for most recent iPhone models. Android? I would be LUCKY if I can even find a case for my Z Fold 7 that's not... plain black or some variance of that. Seriously, try Amazon right now and see for yourself. I get far more options for accessories that I can strap to the back of my iPhone... than I do on the Android side.
3. Which brings me to this point: MagSafe. Wireless charging is of course not the whole point. Android has wireless charging, too. But the point of MagSafe goes beyond wireless charging. It can be used to magnetically attach the phone to a stand, attach it to a car mount, attach a wallet to the phone, attach a battery to the phone (and keep it there), etc... And sadly, there's no alternative for this in Android world that's "standard". You can indeed just purchase a magnetic case, but see #2 above: can we even get anything other than plain boring black?
4. It's minor but here's a few more things and I will just group them all under this headline:
If I want to annotate or sign a PDF with my phone or iPad? No problem. Save the PDF to Files, then just edit it, doodle or whichever. When done: save and email. It's super easy. What app on Android can even edit and save doodles to a PDF? Note: I have tried Adobe Acrobat as well. It's not that seamless.
If I want to
select texts in an image on my iPhone? No problem. Just select naturally, then copy. Done. Works with most of the languages I have tried including Japanese and Chinese. What app on Android does this? Note: I gave up trying to look for one but maybe someone knows something very obscure that works.
While watching a video in Safari, if there's something too small in the scene that I cannot see, I can simply just... double pinch to zoom in to the video, or double tap! Note: as far as I can tell, ONLY the Samsung Internet Browser on Android allows something similar (but not quite). Nothing else does anything similar. Chrome on Android is now a joke.
As mentioned above, Safari syncing. But to me, it's more than that: all of my passwords, contacts, iCloud documents, etc... are visible across all devices I own at all times. If there's something that's not synced, I can just Airdrop it. I don't need to remember passwords to all of my apps anymore. The apps work with password syncing too. Is there anything similar for Android? There is but it's not integrated into the phone. You have to use a separate password manager that... ironically, you need a key or password to access. Yes, I know about Samsung Pass but that one just doesn't work the same way.
This is on a per-OS basis, but accessibility settings in my iPhone allows me to set custom font size per app. Is there anything similar for Android? I could not find one that's not a custom OS or that does not need ROOT. And ROOTing an Android phone is a whole other ballpark in terms of security concerns.
There's a bit more but those are the ones off the top of my head. This is me speaking as someone who uses both an iPhone and an Android phone daily. Android has its own benefits (more of an isolated standalone computer) but it also has its own massive drawbacks in the overall "ecosystem" that I find... cumbersome to work around. Others can disagree, but again, the above are the dealbreakers for me on Android.
