I was the guy with all my keys and fat wallet with all cards and phone + Multitool knife.
Then I got inspired by my sister that travels a lot and tries to optimize for what she REALLY needs.
First I realized that most of my wallet is useless. I started carrying a smaller flip style one with my most used cards and some cash.
Then I reduced my keys to a carabiner with sorted keysets on keyrings, so I carry only the needed ones. Home + bike + cellar for daily use. Home + family keys for vacations. Home for going out. Added a very small key knife and a bottle opener that is part of my daily driver but left when not needed/forbidden.
The current setup is a phonecaee with space for 4 cards and maybe 3-4 bills. And my key setup.
Yes you have to remember to take some Special thing. But usually I have my old wallet in my backpack when traveling or when needed.
I actually use an Orbitkey holder to keep things neat and less bulky. Strongly recommend adding their multitool to that too, which I find super helpful.
I have a Secrid Miniwallet for cards and some cash, but usually I just use Google Pay so rarely even have that with me now.