But it's a bit of a pity that it still doesn't have an iPhone version, and since I switched to iPhone, I can only use my Electrum on my laptop.
Either way, you should still consider owning a hardware wallet as it is still the safest option.
You can use blue wallet if you're looking a non custodial and open source wallet as good as electrum, it already support for iOS.
I think some people already skeptic about hardware wallet due to ledger had announced they will share encrypted private key to third party, the best choice is you need to set up your own cold storage.
So the best to worst wallet is:
1. Own created cold storage
2. Hardware wallet from centralized company
3. Mobile non custodial wallet
4. Custodial wallet
After the issue with Ledger, people also stopped trusting hardware wallets and switched to using Trezor as an alternative. Although Trezor is superior to Ledger because it is open source but as you said, all of them are produced from centralized companies so it is difficult to trust them again.
I switched to an old laptop running Linux and integrated Electrum to store my bitcoins. Of course, it's always offline and just for storage, I find it more secure than hardware wallets.
Regarding the best hot wallet, I only trust Electrum.