Crypto is very exciting. And one of the most exciting things about crypto currency space is a full anonymity. What does it mean? When you "create/generate" your "wallet", it simply basically pics up a random private key from a huge space(really huge space) and creates a public key which becomes your address. This concept has its good and bad. Good - because the key space is so huge, it is technically impossible to bruteforce your private key. Of course there is always a chance the random generator accidentally points to the same seed, but... no. Bad: anybody who will be aware of your private key automatically becomes an owner of your wallet. And there is absolutely nothing you can do about it. If you get any of my private keys - you own my wallet, same in reverse. There is no "legal" bind between you and your private keys. Well, you wanted anonymity and decentralisation, right...? So what do we do about it?
First of all we need to make sure the seed phrase/mnemonic/private key is generated preferably on a medium which is completely offline. Get an old phone, load a web page with a key generation algorithm, turn all connectivity off and generate a key. Never turn it on again or wipe all data offline. Then write your phrase/mnemonic on a piece of paper, re-arrange words in the order you remember and put in in the safe place. Done. Secure? Secure. Convenient? Not that much.
What about Chrome extensions? Metamask, Polkadot.js etc? The fundamental truth is:
Your private key should be generated on medium which stays completely offline at all times.
When you generate a private key using Chrome extension there all sorts of things that can go wrong: your screen may be captured, extension may be compromised, another extension may gain an access to wallet generator etc.
Now here comes a part when we think of a device which would always store the private key secure, offline, yet allow us to authorise transactions and confirm we own this private key without actually revealing it to any medium connected to the network. Here comes the Ledger.
The reason I use Ledger (Nano X) is because it ticks most of the boxes I care about regarding security/long term usage. The key is generated offline on device, and it prompts you to write it down on a physical card and then reconfirms that you wrote down the phrase correctly. After that, you simply set up a pin number to authorise transactions. Done. What if you lose a Ledger? Not a big deal. Pin protection accepts three attempts and then wipes the memory. In the end what matters is your phrase written down on a physical piece of paper. Buy a new Ledger and import the phrase offline, done. What if the battery dies? The battery warranty on Ledger Nano X is 5 years. After it expires - every time you connect device to USB it boots up and voila. What if somebody knows a pin from your ledger? Well, this one is more tricky. You must destroy the ledger or change a pin ASAP since pin grants an access to private key (without revealing it, but enough to do any transfer/signing activity).
Also software shipped with Ledger is pretty neat - Ledger Live for mobile and computer. It allows to buy crypto, swap and even stake - my favourite feature for Polkadot since many people are getting lost doing it on Polkadot JS platform. You may ask, but you can do the same on Kraken! Yes, but your key is not in your custody, while here it really does belong to you and you only.
Can Ledger be hacked? Of course, like any digital piece of equipment, but not in foreseeable present/future. You can apply the same question to a private key bruteforce etc.
Is it worth those $200-300? Definitely. At least in my case/opinion. Yes, the only think which matters is a set of 12-24 words which makes your private key generated, however what Ledger gives you is a security and most importantly - convenience. I believe if you have crypto assets which cost more than a price of a Ledger - you should definitely have one. Because as I mentioned above there is no legal bond between you and your private key, whoever knows it - owns a wallet and its content.