[ploum]

My laptop is USB-C.

Everything else I have is micro USB: my phone, my ereader (PocketBook), my reMarkable tablet, my bluetooth headset, my bike GPS, the lights of my bike, my portable batteries.

I fear the day I will have to replace all of those with USB-C because, currently, I can travel with only one small charger (as long as I don’t take my laptop).

[chx]

I do not follow your reasoning. There are extremely small C chargers and if the replacement is gradual, you could also just carry C male-micro USB male cable(s) and micro USB female to C male adapters. Such adapters adhere to the specification, it's C female to legacy USB which is not.

[vel0city]

Just get a USB-C to microUSB adapter to put on the end, and you could charge it all with just your laptop charger.