It gives more working real estate for those who need it, and packagers can choose which way they want to ship the applications
In reply to your question, you can always bring the menu back, by holding down [Ctrl] and hitting [M].
There is also usually a menu option no more than two clicks away.
@kde In konsole, the change clashed with the Helix editor, where CTRL+o was suddenly opening the hamburger menu instead of being forwarded into the terminal.
In the keyboard shortcuts config, there was no option, so I was unable to disable Ctrl+o for the hamburger.