If you want to run things in the floor just make a channel instead of burying a tube. Conduits and vac lines will likely run mostly around the outside edges of the shop so you can cover the channel with a board (set in so it's level) and you won't likely walk on it, it'll be behind the equipment. I see this in factories all the time, they cover it in diamond plate but that's not necessary, a 2X6 will work.
You can have the advantage of underfloor routing without the permanence if buried conduit.
This idea will solve any access issues. A channel with a 2 X plank that rests either on a rabbett cast into the concrete OR 2X's placed in the channel at a lower height to support to planks resting on therm above.
Personally I would not run any utilities or air supplies under a slab the main reason being shop layouts change, work flows change, and new machines may be added at a future date. This is figured out after the shop is built and you actually start using it.
That said, I do have one section of duct under slab to my table saws to eliminate the obstruction of the drop down.
The advantages are mostly of a "safety" issue from tripping hazards.
A 4" pipe can be a large floor obstruction, so most shops run the DC pipes overhead. That method has it's own issues..... conflicts with other overhead utilities like lighting, visually unappealing, gravity works to keep things at the bottom of the drops, vertical drops to machines that get in the way of swing long boards, but nothing too
much to deal with, however.
My solution requires floor space for 2 Jet 1100's on mobile bases that get wheeled short distances to the machine being used at the time. I use short 4" flex hoses to reach the planers, jointer, drum sanders, and table saws. I use quick disconnect fittings to minimize change over times. The 3 joined table saws have a common 4" suction pipe underneath which terminates near one of the Jet 1100's for easy access.
Running DC pipes under a slab is very labor intensive and would require a pretty well thought out floor plan..... subject to change in the future. My shop layout has gone through about 4 changes, getting new tools, removing older ones, etc. The only tool that has not moved is the ultra wide 3 table saw setup. I guess, if it were me, I wouldn't do it.