My question is, this is how it works similar to a hardware wallet, we make transactions then need permission on the device that stores the private key to sign the transaction and then broadcast it again on the online device.
If there is a method like this, why do most people buy hardware wallets, are they easier to use or safer than the methods above, or do they just look like they have a lot of bitcoin assets if they have a hardware wallet?

in my country, many influencers suggest buying a hardware wallet because of the security issues of local exchanges, and those influencers suggest not to store assets of more than 1btc on the exchange and if it is still below 1 btc it is okay to still store it on the exchange, as written above (not how many assets are stored but how long the assets are stored in the coldwallet) I agree with this.
Because a hardware wallet is already a unique device for signing transactions in isolation and is presumably more secure than a hot wallet.
Also, if you don't have a second PC/laptop or an old notebook, buying a signing device like Passport, coldcard mk4/q, bitbox02 can be cheaper than buying a new computer just to sign offline transactions. Many air-gapped hardware wallets have a camera to scan QR Codes, so it's easier to sign the transaction on the hardware wallet and then transmit the signed transaction to the online device.
Also, if you don't have enough technical knowledge, you can end up compromising both your online and offline devices where your keys are stored. With a hardware wallet, there's presumably less chance of this happening (unless you compromise the seed phrase by writing it down somewhere online, you should write it down on non-propagable media such as paper, steel plate, etc.)
I recommend hardware wallets for both beginners-intermediate and veterans, for me, the only basic requirement for a hardware wallet is knowing the importance of the mnemonic phrase, passphrase and an amount that is sufficient for you.
I recommend this site to improve your knowledge:
https://learnmeabitcoin.com/beginners/wallets/