The name gives it away - it's a tool that you can use to manage your passwords, by being a secure location to store your account details.
It may help to think of it like the contacts list on your phone. You don't remember every person's phone number, because you don't have to. You can just click the person's name, and their number is ready for you to use.
With a password manager, you don't have to remember every password because it's stored with other details that make it easier for you to search, like the URL and your username.
Apart from being more convenient (as described above), there are several other reasons to use a password manager - such as increased security, organization, and efficiency.
With a password manager, you can remove that risk without taking on the heavy mental load. Using a manager means you only have to remember one password (the master password for the manager), and then you can use unique passwords for all your accounts easily.
Password managers can also generate new passwords for you to use, ensuring that they are stronger and more unique than "Password1" or "YourNormalPassword+1."
The stronger the password is, the longer it will take to crack. If you want to see how long it would take to crack different passwords, check out: Password Monster.
Most password managers can also provide a review of your current accounts and passwords. With this, they give you a report of which accounts have been breached, which accounts use the same password as others, and other relevant information to let you know which ones may be at risk and need to be changed.
They can also help protect you against phishing scams. Phishing scams are a type of attack where the scammer pretends to be the actual site you want to use. They normally work by sending you emails or texts saying you need to do something on the site (and urgently, for example, an email stating “You just sent a large amount of money to this other place” will make you panic and want to log on to cancel that), and then providing you with a link to a site which looks almost identical to the actual site to get your account details. Password managers can help because it doesn't matter how good the fake site is (and presumably it is good if you've gotten as far as trying to enter your details), the password manager won't auto-populate the details if the URL of the site is wrong.
You can also use a password manager to securely share passwords. If you need to give your login details to someone else, rather than sending them the password in a way that could be read by others instead you can use a password manager to create a secure link to share instead. By sharing details this way you can also control other aspects such as how long they can view the password, and whether the link will only work for them or anyone with a copy of the link.
Technically yes, but this is still a safer method than reusing passwords, and a more practical method than having you try to memorise a large number of complex passwords.
No password storage method is without risk - reusing has a greater risk of being cracked, and remembering everything has a greater risk of you forgetting them.
Password managers are more practical (meaning you're more likely to keep using them because they're not awful to deal with), and also they're more secure than most websites.
There are a lot of in-depth articles about how password managers work, but the gist is that they work in such a way that even they don't know your master password, meaning that even they can't get access to your passwords because everything is encrypted. So even if someone does get into their servers and steal your data, they still have to crack your master password first.
You can keep everything even more secure by enabling two-factor authentication as well. Then even if they manage to get your master password, they would still be prevented access unless they also had the secondary identification required.
What all this means is that yes if they get in they would have access to all your accounts - but they would have a much harder time getting access in the first place.
Using a password manager is not only convenient, but it’s also essential for online security. It helps to eliminate the risk of using the same password across multiple accounts and increases the strength of passwords by generating new ones. They allow you to be more organized and efficient by keeping all passwords in one secure location and auto-filling them in when needed. While no method of password storage is completely risk-free, password managers are a practical and secure solution to the problem. That’s why the “technical” people you know want you to use one.