I think the difference is that if Figma's website goes offline, you lose all of your figma stuff. If penpot gets acqui-killed, then you can just clone a version that you were comfortable with and keep going.
Like last week when Safari 16 broke any use of the command key on Macs and we received 5+ reports per hour until it was fixed.
Of course, I’ll be on a 15 year old OS but the answer appears to be “yes”.
Not the case with Figma or other hosted tools. Not even the case with Photoshop or tools that require license checks / internet connectivity.