I’m not sure we don’t share a bit of common ancestry. I think your yellow handled knife there is an AG Russell, but could be wrong.I've increased my pocketknife collection this year but so far have found 2 to be firm favourites.
At home and out and about it's a Case Sodbuster Junior carbon.
For work it's a QSP Penguin Mini. I know this is a locking knife, so doesn't really fit the OPs criteria, but the one handed opening massively increases its usefulness at work for me.
Not all these are in daily rotation, but those that are are in the second pic. The Civivi Baby Banter is a little gem of a knife, and only upside down because the torch that was on turbo to provide the lighting was getting too hot