To be honest, technology isn’t the main factor to be amazed with but the fact that we are going to get such AAA games even when iOS nor Android are the market for it, you know, they are no Candy Crush or any regular gatcha game…
I don’t even have an iPhone anymore, but even if I did I wouldn’t get those titles there, I will never forget Apple (or Epic or whoever fault is) to turn their back to Infinity Blade games, the third one even was a tech demo with an iPhone presentation FFS! (Does that ring a bell BTW?), and so many other good AAA like games have been lost in the time, especially with iOS.
I recommend the Chinese handhelds too, I only have a Retroid Pocket 2 (too old), Anbernic RG351V and a Miyoo Mini V2, I only use the RG and Miyoo, the later is great for simple games/quick burst but due the lack of wifi antenna it is not possible to use Retroachivements with it… which it is possible with the RG351V, also the Anbernic has quite the better hardware without a question.
Notice all these aforementioned handhelds would only give you a pleasant experience up to PS1 (minus Saturn), so if you want a handheld that can at least give you PSP, Dreamcast and N64 I’d pick an Android based Retroid Pocket 3+ Anbernic also have some capable models for this. it is worth to mention that if you have a relative new Android phone you already have a capable emulator with you all time, you’d only need a holder or a telescopic joystick to enjoy an almost endless library of games (despite having a PSP I finished Persona 3 Portable with my phone and a Razer Kishi controller).