[kyleb]

We use a lot of "push to connect" fittings at work - not because they are the best or even good - - - we use them because they are cheap, easy to install, & good enough (We don't care if the air leaks down since the air compressors are provided by others . . . )
We also use fittings with pre-applied sealant when available. We use a paste sealant instead of tape as the tape can cause more problems if it gets inside the air system.

Inside the "push to connect" fitting is a rubber "o-ring". As they dry due to age, they shrink & crack. That is why I use compression fittings on my Newell.

The DOT fittings provide more support for the air line for a longer lasting leak free connection (a vibrating line can wear out the o-ring seal or allow the tube to crack.)