From what I understand, ps2 emulators can't really run ps1 games, so that's the reason for that. Not to mention that most emulators are made so people can casually play a game rather than it accurate to the hardware itself. So if a ps2 emulator would work, more than likely it'd load faster than official hardware.

As for emulators we use, at the moment I am using ePSXe 2.0.5. I'm certain that's what other people are using, but that's what I am. I hope this helps :)

Muppet RaceMania

Is ps2 emu as good as PS1 or is there a difference

Thicchunter

The Simpsons: Hit & Run

Peggle Deluxe

SuperTux

Slime Rancher

Golf It!

We Bare Bears Webgames

Jackass: The Game

Karlson (Itch.io)

Phasmophobia

Shotgun Witch

Going Under

The Last Spark

Charlie in the Moistverse of Madness

Pico World Race