Little things like plasters make all the difference IMO.
You get minor MTFU injuries and major “MEDIVAC” injuries requiring specialist help. But you also get stupid injuries that can ruin a days riding like a blister from the back of your shoe after having to walk further than planned at the start of a long day riding…
I carry a large dressing for severe haemorrhage, sterile water for cleaning eyes out, duct tape for everything from immobilisation to wound closure, codeine for my generalised pains, blister plasters and always a spare energy gel/bar.
Anything more than that is extra weight and un-needed.
(though I did once chuck my first aid kit from a mountaineering trip into my camel back for a trail centre ride and came across a downed rider with a cut chin, opened up the kit and all my cannulas fell out…WALT-tastic!)