Well, you've taken it a little harsher than intended, that's for sure!
Seriously, the factory service manual, if that's what you are calling the "service handbook", has the exact same maintenance chart as is in the owner's manual. Yes, there are several items the chart says to "inspect" every 5,000 km, but the important ones that
do need doing only come up every 10,000 km. Those are the ones you want to have done.
It would be interesting to see what services performed are listed on the dealer invoice for those 5,000 km visits. I'm guessing an unnecessary oil change at least. There's $100 easy.
Going by that chart religiously is what RE wants you to do to support their dealer network, for service is the money maker, as you can see.
Bottom line here is, you don't need to go in every 5,000 km, for the "inspect" items rarely need attention.
You did come here to ask " does anybody else think that 5000km service intervals are a bit too frequent"? I think I've tried to explain that to you.
Now, just on the off chance that you might change your mind about trying your own hand in doing a bit of maintenance, here's a RE link to a load of videos they produced to help owners do many of the simpler tasks.
https://www.youtube.com/playlist?list=PLT1BEDU54E1SKBG28gF49AclawHddstLm