My first interaction with Ether network back in 2017 when I use metamask extension to trade with ddex and I like the extension as it was one stop place for all my holdings. Metamask is the only & safest extension available at that time to use with third party websites to send transactions and store ERC20 tokens.
One good advantage is that you can import any ether wallet into the extension and keep track of your holdings. You can even use metamask extension to stake coins on any third party website & enjoy the profit sent directly to the wallet attached.
One big disadvantage of metamask wallet is that in case of browser crash you cannot recover your wallet if you dont have keys and it is easy to hack and sign transactions on your behalf as there is no alert system. Earlier You could only install metamsk extension on Chrome but now Brave browser provide the inbuilt metamask extension and you can even use metamsk extension with mozilla web browser as well..