If you look for stores with good reviews and good sales numbers you're 90% sure you'll get what you paid for. There are some other sellers for these types of devices like LITNXT, and you can even find them on Amazon (usually more expensive).
If you want anything like PS2 or gamecube prepare to pay $150+ for a device, and most likely it will be an android based device like the retroid pocket devices
Most of these ambernic/Miyoo/powkiddy/Trimui Linux devices are aimed to play up to PSP, and some PSP games will run poorly, they're using older cheaper chips, so they're honestly weak devices.
IMO, best case is buying one of these devices for psp and below, and a steam deck or other handheld PC for PSP onwards.. And PC gaming obviously.
I have an ROG Ally, and PS2, gamecube and WiiU runs great, but it feels like overkill for GBA and PS1 for example, so, for older emulation I just use this $60 device
No worries! If you have any questions on the smart pro just let me know, it's the only one of those devices that I have