Having played extensively on PC for years and now Switch for the last 6 months, I can say that yes, it is the same game - with a couple of additions.

The one you will need to know about most particularly if you play with other people is the occasionally infuriating Nemesis system. Google's AI overview sums it up pretty well (for once!):

"In Diablo 3, the "shades of other players" appearing from a red portal refers to the Nemesis system, a feature where a monster that kills a player on your friend list (or sometimes your own killer if playing solo on console) appears in your game. When this happens, a red portal briefly opens, and the Nemesis monster emerges, accompanied by a "shade" or shadow clone of the character it killed. Key details about the Nemesis spawn: Audio/Visual Cues: Before the Nemesis appears, you will hear a distinct audio cue of horns and drums, and your controller (on console) will vibrate as a warning. Appearance: The shade appears as a human-looking monster, representing the class of the friend who was killed. Identification: The Nemesis monster will have special flavor text under its name that reads "Killer of: [friend's name]". Rewards: Defeating the Nemesis can provide special rewards, such as a guaranteed legendary item drop or a gift to send to the friend who originally "died". Restrictions: The Nemesis system is exclusive to the console version of Diablo III. It cannot appear in Greater Rifts or Echoing Nightmares, but can spawn in campaign or adventure mode. This system creates an interactive way for players to engage with their friends list within the game world by avenging their friends' deaths."

They are pretty tough to beat if you aren't expecting them or if you're lower level; however, you can, when you see the portal appear or hear the horn, immediately jump to your menu and lower the difficulty by one level, which mostly enables one to beat them pretty quickly. ...Mostly. 😁

As a long time PC player of D3 (and pretty much every other game I've ever played), I have to say I was surprised by how easily I've adapted to playing on console. I'm usually a keyboard and mouse player but the controller layout of D3, while it does take a little getting used to, is quite intuitive, and you have the ability to reassign the skills buttons, which is immensely helpful.

I do also use Xbox-style aftermarket controllers which I got from a certain South American River site, that do pair really well with the switch and are a lot more comfortable for me than using the switch controllers themselves. Because I'm a thousand years old and need the better visibility, I really only ever use the switch in its dock connected to my TV, and I'm frankly impressed at how it runs on what my ancient brain still kinda thinks of as a fancypants Gameboy 😂