I actually bought one a while back for the emacs metakeys issue which had 4 buttons (it was originally designed for turning pages on a pad while playing music). It worked pretty well while it lasted, but broke after like a year.
Having a qmk split keyboard (the iris specifically https://keeb.io/collections/iris-split-ergonomic-keyboard) was a more lasting solution that also solved some other ergonomic issues. Now my thumbs do more than just thonk the space bar. Control, shift, space, meta, backspace/delete, enter alt and esc are now done by thumbs instead of pinkies.
I think resourcing foot pedals from the music world (guitars and bass mostly) would be the way to go, they're designed for heavy use and would likely be much more durable.
A lot of these USB pedals are about as sturdy as piano sustain pedals.
More literally though, the Logidy UMI3[1] is a MIDI-over-USB foot controller that uses guitar pedal-like switches. It's designed to serve as a hardware interface to software loop control, but you can use a MIDI yoke or translator[2][3][4][5][6][7][8] to turn MIDI input into keystrokes, game input, etc.
Having a qmk split keyboard (the iris specifically https://keeb.io/collections/iris-split-ergonomic-keyboard) was a more lasting solution that also solved some other ergonomic issues. Now my thumbs do more than just thonk the space bar. Control, shift, space, meta, backspace/delete, enter alt and esc are now done by thumbs instead of pinkies.