IMO it all depends on the type of soil you have to wether a raised bed is a good thing or not.
Our allotment is very well draining you could have an inch of rain overnight and be able to get on and dig it next day, when I first started on my plot I put in a raised bed dug the soil out filled with well rotted manure ans back fill with the soil I had dug out, I put my overwintering onions in this bed and they grew very well then the weather turned fine and after a couple of weeks of dry weather the odd seed head started to appear although stuff on the rest of the allotment wasn't troubled to much the bed was a nightmare to keep any moisture in and I spent a lot of time with the hose trying to save my onions