With everything being so weight centric in the cycling world why havent skip tooth chain wheels become a thing yet? Metallurgy technology has progressed to be lighter and stronger than the old war era bikes. So why hasn't a company tried to make something similar?

"Skip-tooth" chainrings were designed for use with bar-link chain, which is heavier than modern roller chain.

I have a couple of skip-tooth freewheels from the '70s; one Shimano, one Suntour. These are wide-range 5-speeds with the skips on the 28 and 32t sprockets. Helps get the flat-sided period chains on to those big cogs.
Modern (SIS-era) ramped cogs and chain profiles eliminate the need for skip-teeth.

More teeth mean better chain engagement, especially under high loads or acceleration. The people who care most about a few grams of sprocket teeth, ie: Racers, also would care much more about throwing a chain during a sprint.

Interestingly, with the rise of 1x, we're seeing a lot of narrow-wide and hooked-tooth chainrings to promote maximum chain engagement.

Other than (very small) weight savings, what is the benefit you expect to see from fewer teeth on the chainrings?

Yea & even inch pitch chainrings on 1/2 pitch chains were generally, not for derailleur bikes...

but track bike use.. and cruisers..

skipping 17 out of 34 was done on some freewheels, decades ago,

and the 15t cog for the Sachs special 2 cog IGH driver on the 1st, 3 by 2 6 speed hub for Brompton ,
had every 5th, 3 teeth shorter, as a shift gate aide from the 13t next to it..


now cassettes do that tooth slipping for the shifting purposes,
and made all teeth a bit reduced over their single speed predecessors.




/..

I didn't really expect any mechanical benefits. Just a random question I had as far as weight reduction.

I did not know that. Makes perfect sense. Thanks for the enlightenment.