I carry both.
The hand pump is for general use, because you'll never run out of atmoshpere.
The CO2 cartridge is only for if I ever need to seat the bead in a tubeless in the god-forbid situation I ever get a cut the sealant won't seal & the bead comes un-seated. It's never happened, but most tubeless, if patched, will stay inflated with out sealant for quite some time...long enough to get out of trouble, anyhow.
I also carry a plug kit, & standard vulcanizing patches, a valve core, valve core tool, a master link, a multi tool, spare 2032 batteries for HRM/powermeters & a tool for the powermeter transmitter/cap. I should probably carry a chain breaker.
It all fits in a standard water bottle I transfer from bike to bike or put in my jersey pocket.
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I shouldn't have to "make myself more visible;" Drivers should just stop running people over.
Car dependency is a tax.