There's nothing wrong with wanting to stick to original hardware, if you already have it or can afford to buy it.

Setting up a Pi or other single-board system as a dedicated retro game emulator is also an absolutely valid choice IMO. It's a fun, generally affordable little project that you can tinker with forever, e.g. changing cases and controllers, UI tweaks, ROM file organization, per-game settings optimization. But I don't think that it's ever been the "best" emulation option for anyone who didn't already have their heart set on "doing something fun and interesting with a Pi".

The smartphone you already have, dedicated retro gaming handhelds, Android TV boxes or sticks, and cheap/secondhand/already-owned PCs (desktop, notebook, or kiosk) all arguably match or exceed the performance and value-for-money of any Pi-based system.

Yet in any thread where someone new to emulation is asking for advice, there's always a flock of folks who suggest getting a Pi like it's the only game in town. It honestly baffles me a little. Especially because almost all of them are just running a pretty frontend over Retroarch, and Retroarch is available for virtually every modern consumer computing platform (and so are a lot of pretty frontends, if that's a selling point).

For context, I've got a dozen or so retro systems, but I prefer to emulate as much as possible.