Pointless unintuitive feature that’s replaced with simple press and hold.

Unintuitive for you, perhaps. I found it more intuitive than the press and hold (until it became ubiquitous), since it made more sense for a preview. Press and hold, in my mind, is more for secondary menus and alternative options, like mass-selecting.

The air gestures were also nice if I had my hands full, since they worked without turning the screen on, and without touching it, although they leaned more heavily on the gimmick side of things.

Slow and unreliable compared to fingerprints. Anyone actually used it?

Yes. I use it a lot when I have my phone on a stand, or when I have gloves on. Fingerprint readers don't work through gloves, for obvious reasons, and it's less effort than having to fumble around with my phone and my gloves, especially when I will be putting the glove back on afterwards.

Since my phone also has the fingerprint reader on the back, rather than the front, it also makes it much easier to unlock my phone without picking it up, which is nice when it's on its wireless charging pad, or I want to quickly check a notification or something, rather than needing to pick it up.

As for speed, I've not found it that much worse than the fingerprint, especially once the camera's fired up. The hard part tends to be aligning yourself just right, and that you need to tap a "confirm" button compared to the one-click that fingerprint does.

Who needs these things? Weather apps work just fine. Rather use the space for battery.

The space won't be used for battery. It's a small chip on the PCB, and Samsung would either keep it around for other sensors, or would leave that space blank. Having a tiny battery protrusion like that is silly anyway. Having a little dingle like that would just make the battery more likely to be damaged and erupt into a violent conflagration.

I personally found it handy, even if it was underutilised. Sometimes you want information from within the house, not outside of it, and if your phone can fetch that information and present it, you don't need to go and buy a separate hygrometer and air pressure sensor, and carry it around, or have to feed that information via an external service.

Unless you’re looking to vandalize public tvs, just replace it with any number of wifi/bluetooth remotes.

Assuming that your TV comes with support for those. If it doesn't, such as if it's an older television, then you would be out of luck.

Personally, I used mine a bunch back in the day, just because it was nice to be able to fire up the VCR, Amplifier, and TV all in one button, rather than a bundle of loose remotes, but that's more of a first world problem, and less of an issue these days, since television is on the decline.

More importantly, though, the phones aren't cheaper despite the loss of these features. The phones just get more expensive, even though they had fewer sensors and features like that.