Slow cooker - worse in what way? You need less liquid than the oven, if it's watery you can leave the lid off got a bit to reduce
CupoTeap
worse as in less full of flabour, and the watery texture is nothing to do with volume of liquid.
example - beef casserole. In the oven, browned, thick casserole gravy, imbued with the flavours of the meat, onions etc
In slow cooker, even if there is little liquid, it just doesn't pick up the flavours and richness of the ingredients the way it does in an oven.
Th eonly way to make it come even close is to fry all the ingrdients first before putting them in the slow cooker.
If you do that it becomes a massive long hassle version, needs ot be done the night before due to timing, (and then what? Cool down in fridge over night and reheat inslow cooker?)
Or - bung it all cold and raw into my huge casserole pot and stick in the oven on a low heat for 4 hours.
I have eaten loads of things made by other people in slow cookers, and to be honest almost every time I would say it is watery in flavour (again, not due to volume, due to consistency) and less good than the equivalent in the oven. I only know kne person who makes decent slow cooker stuff, and when I do it in mine it isn;t as good, so I use her recipes and do them on the hob/oven