Is there a hard wallet that connects to an iPhone or are most of them thru androids. Also which hard wallet would you say is pretty user-friendly?
I would only handle a crypto wallet with at most some pocket money on a mobile phone. Why? Because a mobile phone is easy to loose and is a target for theft. Mobile phone users in a lot of cases do all sorts of internet and games shit on their mobile phone, the cheaper the apps, the better. And what do you think are free apps paid with? Your usage data or ads! Seriously, not the best environment for privacy and safety. But, you do yours.
Hypothetically speaking, if let’s say your computer is compromised or has a Trojan in it and if you connect your hard-wallet is it still pretty safe?
Normally there's no protocol or software in the hardware wallet's firmware that would allow the extraction of your wallet's main secrets, the seed and your private keys (actually Ledger Nano firmware has software for key extraction in it and Ledger Nano firmware is closed-source, so you don't know what else shit is in there; you seem to favour the closed-source obscurity camp). Ledger crap? In my humble opinion a poor choice. Anyway, I'm not here to judge...
I’m assuming with a hard wallet, your keys are on the device so if you happen to misplace that wallet your funds are also gone? You can not use your keys to open it in another hardware wallet?
Try to gather some knowledge how so-called BIP39 HD wallets work (basically every hardware wallet is internally a HD wallet). They are based on a random secret of mostly 128 or 256bit length from which by a cryptographically safe procedure all private keys are derived by a deterministic recipe. All you need to recover your wallet are the usually 12 (128bit secret) or 24 (256bit secret) mnemonic recovery words. Those recovery words you have to keep offline and secret and redundantly stored safely.
I don't care about ETH but a good place to learn about HD wallets is e.g.
https://learnmeabitcoin.com/technical/keys/hd-wallets/.
You could setup one particular HD wallet in multiple different hardware wallets and they would all produce the same private keys. That's the beauty of HD wallets.
It’s pretty brutal that I can’t recover funds, so you’re saying all these huge hacks where people steal 60 million worth of bitcoin from larger exchanges. Everybody just gets away with the money? The feds or government agencies can’t catch them, because if they transfer it to an exchange like eXch, it’s game over then? That’s just crazy considering how much money we’re talking about in some of these hacks
Some thieves make mistakes and get caught. E.g. the hacker and his wife who robbed Bitfinex years ago got caught. But depending on how much has been stolen, a lot of thieves get away with it.
Your loss was likely avoidable (I'm not entirely sure as you refused to answer some of my questions I asked earlier). I don't know who determined facts when you say, your computer was hacked. Is that only belief or do you have real evidence? There are many different cases documented in this forum how users screwed up with wallet security. No-one said safe self-custody is easy!
Maybe a bit over-the-top, but if you want to learn about good self-custody, have a read of the PDF at
https://www.smartcustody.com/.