Mixing tube epoxy sealing compound

Is there a reason why you mix by hand on a bag and not just use a mixing tube?

Such as: https://www.amazon.com/SODIAL-Static-Mixing-Syringe-composite/dp/B06Y2KMRNC

It's probably related to the size of the job. For very small jobs the point of the mixing tube is probably too large.

It is a matter of habit. I mix compound by hand and then apply with a toothpick. Also If considering mixing nozzle - there will be lots of waste of compound that will be left inside Nozzle.

I also mix the epoxy by hand and insert into a medical syringe with a 1.2mm needle (cost next to nothing if you buy a box of 100). The mixing tubes are more for industrial application, I feel, where it does not matter so much to waste lots of material. It only makes sense if you plan on using the full cartridge at a time which would be unusual in our application.