I'm not saying they're always going flat out. They have the capability of going that quickly.

And guess what these mods do? Up the limiters on speed and put a battery that is far too large for its purpose.

I've seen way too many e-bikes zipping past at something closer to 40mph.

Rain’t

You can do it yourself with a known good battery. The only downside is that settings will say that the battery is not genuine, but otherwise it will work.