Perspective: Former college robotics team member a while ago (2022) (IEEE SoutheastCon)

I definitely see niches for both. Even if you've got some experience an Arduino uno or mega is just an atMEGA with good software support and IO headers.

We'd usually use an RPI and Arduino - connect our 'out of the box' modules to the pi, pi to arduino via uart serial, and wire arduino to the meat and potatoes. The RPI's IO was generally not as good in terms of latency but also if the wrong wire gets crossed suddenly we'd have a dead Pi but the Arduino would shrug it off.