Agree with much of what's been said. It really depends on the child. It's totally not "necessary" at this age -- unless they're really interested in it, of course!
I pushed loads of handwriting on my son from a very early age. He hated it and fought me at every turn. Years and years later, it was still atrocious. I didn't know any better at the time. He's now 12 and finally seeing some improvement -- and interest -- using Penny Gardner's Italics book. I wish I'd held off and followed him more. It turns out he has various physiological issues, writing is physically difficult for him. I probably just made things worse.
My daughter, on the other hand, is only 3.5, and has been able to write a few simple letters since before her 3rd birthday. She just made a 'valentine card' for me a few days ago, and wrote "mom" on the envelope all be herself, perfectly. When she sees her brother doing his handwriting practice, she DEMANDS to do some herself as well. I'm using some of the Italics book with her, but also some d'Nealian worksheets downloaded for free off the internet which have more tracing, so it's better for her right now.
She loves it, and demands it, so we do it. It's totally not "necessary" for her because of any arbitrary curriculum demands -- we just do it because she wants to. So if your kid is NOT particularly interested in a handwriting book right now, and you want to simplify, then by all means leave it off. He'll probably be doing a little writing here and there anyway (it's hard to avoid it), just gently help when he wants help with letter formations. And yes, lots of fine motor skills practice is great too.
Drawing! Kids love drawing, and painting, and picking up small objects to sort them into ice cube trays (with tongs too is great)... it's all great stuff.