Weird Question...

[Darryl's Manual]

Okay so I started rereading the series (again) and I had a weird thought/question. Does anybody notice that for the first 4 books, give or take, a number of spells have, for lack of a better term, "ingredients"? SYWTBAW has numerous items necessary to open up the Worldgate and sugar cubes for the timeslide. Others only required reading the spell aloud to work. Is this like some sort of detail error on DD's part when updating the stories or what? I have this weird theory that perhaps as the spells get more complicated they rely less and less on physical objects...except that made no sense when I started trying to use that theory, so I'm not entirely sure. Lol anyone got any ideas or an explanation that would make sense?

[SpacePen]

I always thought they were kind of like training wheels. I.e. if you aren't that fluent or well-versed in the Speech yet, you can use a physical object to "help" the wizardry work, to help it stay on track. But when you get more used to the Speech - like if you've used it for years or decades - you don't need those training wheels and maybe they can even get in the way of the fancier and more subtle stuff you want to do.