Q Is it necessary to have raised beds?
Not necessary to have raised beds, but most people do.
What with bad knees and bad backs,a lot of more mature gardeners prefer them. Also it is good to have the pathways defined
I have a 22 ft with a large center bed which cant be reached from the path way, so I have a couple of flagstones to step on when I need to access that part of the bed
Here is an example of a stone pathway and no raised bed