Carry on luggage is a must for me even though the rule of thumb means only one bag plus one small personal item. With some of those small regional jets the airlines are using to get you to the closest hub, that can be a problem, especially if you’re not first to board. (only one side of the plane has room for luggage)
It is difficult to lose your luggage if you have it with you but I came close a couple of times. Once I accidentally left my bag in an airline lounge during a stop-over and realized it as I arrived at the gate feeling a little light. Another time they made me leave my suitcase by the small plane so they could load it underneath with the promise of me getting it as soon as I deplaned….well they forgot to load it; however, I was watching out the window and let them know in time!
Many of the European budget airlines limit your carry-on by weight (keep in mind that would be in kilos)so that’s when you wear everything that’s heavy. I once flew an airline that weighed the passengers as well!