Bullshit! I don’t agree. Many pros use Hilti, the best brand, full stop, but crazy expensive, followed by Fein and Festool (the basic Festool circular saw is like 600€) Pros who want to pay less use any of the other “color teams”, yellow, blue, red, dark blue… And yes DeWalt is 100% pro, and some pros use Bosch blue. My buddies shop uses Bosch blue for corded, but has gone Milwaukee for battery, as cordless Bosch has been hit-and-miss. I had a 80% DeWalt shop and can vouch for them. I particularly love their sliding miter saws and small, thin waist angle grinders (the unsung multitasking wonder tool). BTW. Angle grinders MUST be corded, except for a very small set of use cases. Battery angle grinders suck pig’s balls.
Also Makita>Bosch blue.
Sadly Ryoby has gone full cheap DIY, like SKIL (owned by Bosch now?) I have an old maybe 18ish Ryobi (Blue) circular saw. Built like a tank, with a cast aluminum foot, that is as precise as day one. Oh well…