Phoenix are one of the big connector suppliers, in the same market as Molex and Amp, who sell most things through distributors, although I don't think they target the big OEM market in the way that Molex and Amp do.

Dynomotion use Phoenix pluggable screw connectors on their add-on boards, as they're a reasonably common connector that can handle the currents needed for most connections. They also use a dual connection connector, that can be fitted so the wiring is either parallel, or perpendicular to the board. It's a useful feature when space is tight.

However, it's also an additional point of failure. If you put too much pressure on the terminals, it can cause the contacts to open up. I had an intermittent issue with a bank of inputs on a Konnect IO expansion board, and it turned out I'd put to much pressure on the common wire during installation, which had caused the contacts to open up and be intermittent.

Direct screw terminals vs pluggable connectors is a perennial debate, but there are pros and cons to both.