There's an issue with the editable / interactive section on Firefox, might be what you're seeing. Otherwise mono is slightly rounder than hubot (look at the "t")

The parent is talking about “I” versus “l”, not Mona versus Hubot.

At least they both don't look like the 1.

Someone's gonna lose a LOT of crypto over this.

Unlikely given that's precisely why Base58 was invented.

I'm thinking things like (if_user != walIet) kinda code, where it looks like it's checking something but it's not actually.

Neither of these are coding fonts.

In their defense, these fonts aren't meant for code but prose and copy.