this is a fairly recent technique that involves drumming your fingers on a button to increase the pressed speed.
for years ive been using a very basic method of this i had figured out to win every game of Pokey Pummel i played in mario party 7. did this by using three fingers of my right hand to drum on my left pointer finger above the A key on a gamecube controller. ive just been calling it drumming for years.
other people have found WAY better ways of doing this with everything from flipped controllers to sex toys.
https://youtu.be/n-BZ5-Q48lE

https://youtu.be/SSzxPklUu9w

--- 2 Players
sometimes games will let you play with both a keyboard and a controller
you can use a 2nd person to mash on one well you mash on the other. this doesnt work with every game cause sometimes it will lag every time it swaps from keyboard to controller and back

--- JoyToKeys/Joy2Keys
https://joytokey.net/en/
this lets you rebind any keys to any other keys
so you can bind 30 keys to 1 button and just mash your hand into the keyboard or roll/drum on 8 keys with both hands well you also press space bar with both thumbs

--- Three fingers on my right hand to drum on my left pointer finger above the key/button that needs pressing

--- Scroll Wheel
binding the button you want pressed to your mouses scroll wheel
some people have expensive mice with unlockable scroll wheels that can reach INSANE speeds
this is the fastest method outside of using cheat programs that ive run into

--- Wired Everything
using wired keyboards, mice, and controllers reduces input lag for higher speeds

im am unable to find the video and no longer want to search online for it for reasons.....
but ive seen someone use a vibrating dildo to absolutely CRUSH people at button mashing on a controller. i have not tried this method
this is Pokey Pummel from mario party 7 for gamecube
https://youtu.be/CY5J5F7UWzo
somewhere on the internet there is a video of a girl playing this game with friends and letting play out most of the game before she starts with a vibrator to blow past everyone and win.
i wonder if people have tried this on PlayStation, Switch, and Xbox controllers
well i cant attest to this method, i have used a pollexnex geltech touch precution foot massager with heat. got it for free with some other stuff after helping an old lady clean her house out and get rid of things. she purchased it and never used it, score. one of those as seen on tv gimmick things i dont think does what it say on the box at all. the one thing it does do is vibrate. its bulky and took a lot of work and time to hold the controller just right on the hard plastic part to get successful button mashes out of it. wasnt worth it and i could go faster without it

how rolling was used to beat tetris
https://youtu.be/mOJlg8g8_yw

https://youtu.be/U9t-slLl30E

https://youtu.be/Uld6lpeD50M