Terminals are only limited in tasks that require graphics content, what a shocker.
For all other cases they're vastly more powerful than any GUI can be, because no developer can (or should, it's unrealistic to ask them to do this) match the amount of complex operations terminal commands can reach with one string or script. With GUIs you also have to deal with different sets and toolkits, like GTK, Qt, etc etc.
There's use-cases where GUIs work better and cases where terminals work better and which ones belong where also depends on the user, but saying terminals are more limited than GUIs and bad is flat out wrong and dishonest.
https://en.m.wikipedia.org/wiki/Free_Beer