As someone who recently decided to "go for it" and get some raw fleece, here is my take on the matter:
Is it a huge load of work? YES
Is it worth it if you just want some nice yarn? No
Is it a fun, interesting and creative passtime/hobby? Yes!
Fleece/wool doesn't become yarn overnight. There are many steps to the process and you will need to invest some money in carders, a drop spindle, maybe a DIY hackle, dyes, various other tools and equipment. You will be spending a lot of time with wool soaking in your sink/bucket/washing machine to get the lanolin out, which requires 2-3 washes then a couple rinses.
Then you have to pick it (pull it apart with your fingers so it's fluffy).
Then you have to card it.
Then you have to make it into roving.
Then you have to spin it.
Then you have to dye it.
Then you have to ply it.
(Not necessarily in that order, of course)
Then you buy silk and llama and get carried away making fancy yarns.
I think it's wonderful but it's not for everyone.