There are plenty of slightly annoying things such as running out of blood for my meter, no longer being able to shove phone, credit card and keys in my pocket and walk straight out of the door (the worst part of this is having to carry a bag around which I don't like), having to ask on every doctors appointment "does my diabetes affect that?", my meter (or pump) running out of power, having to deal with doctors/surgeries/pharmacists (they are mostly pleasant but always running late), ...
But for me it is the hidden expenses such as travel insurance, if you want it to cover diabetes, or keeping a stack of hypo treatments in or the cost of missing work due to appointments, ...
As for loss of spontaneity, I don't find this to be a problem. I walk or take public transport most places (nothing to do with diabetes) so I don't have to check my BG before I leave the house. I have hypo treatment in most bags and pockets, my insulin is attached to me in my pump, so I only have to remember a few test strips and my meter and, if I have a Libre attached, I can (just about) get away with scanning that with my phone which is going with me anyway.