Not at all.
The original tesh was only syntax highlightning, the auto complete functionality was added in like 2014 by LFH (not sure if it is the standard TESH in WEX now?), point is, the original purpose was not the auto complete. Unless I remember wrong, which is possible.
The auto complete functionality is not why TESH is important, the highlighting is. It hurts readability and indirectly understandability.
That said, I am not using wc3 at the moment since Wurst is not up to date with 1.30 AFAIK.
So maybe you are right about the baby part.