When professionals use Arduinos for such use cases, do they use the Arduino software platform or do they use the chio verndors' toolchains? Just curious how the professionals work with these things.
Some people hail from hacker town and will use whatever they have at hand. Some learned on vendor tooling, and would want it to be "proper", and would always try to use a vendor SDK with a vendor IDE. Some learned on vendor tooling and prefer not to use vendor tooling for "familiarity breeds contempt" reasons.
As a degenerate case: I've seen software for an ESP32 board that was prototyped entirely in Arduino IDE, and we almost shipped it that way. Because the prototype team cooked, and when the "make it an actual product team" tried to remake it in ESP-IDF, they ended up with less features and more bugs. They got it together eventually though.
This is prototyping mostly so I'm not sure if any of the Arduino code actually gets shipped with production devices.
For ex, we want to prototype a new mux switch, and need to toggle some gpio from computer. We finished in 1 evening, with arduino and python on host.