What's the name of your boat Gillian? If I get caught in a storm I'm going to raft next you you and all that anchoring gear
It is interesting to see how much some boats do carry. I am of the opinion we do need to carry 2 sets of gear, one a very good primary and the secondary a nice system but one you can dump in a dingy and row out or similar. But more than that I don;t really see any need for unless you are going ocean wondering, like Steve for example. He goes to places like MotoMiddleOfNoWhere so has more need of the extra security and back ups those who cruise local, even extended local, don't need.
So I would say those with much more than 2 decent set ups who do not go offshore, have a suss and think 'Do I really need it?'. I think many will find they don't.
But whatever you do make sure you have your FGF on. FGF is the 'Feel Good Factor' and a massive part of anchoring (and many other things in life) so as I tell people a lot no matter what I say, books say or the 2,656,867 experts who usually aren't on the interweb, you and your family are the ones sleeping on your boat so if you are not happy it will detract from you boating experiance, even more so if your partner isn't happy*. So if you need a 100kg anchor to get your FGF then the best one for your boat is 100kg, even if my boat the sister-ship to yours only runs a 50kg anchor.
* - I'd write that usually as 'if your wife is not happy she will get twitchy and sleep poorly leading to a tired grumpy wife and we all know where that leads and it's not good'. But it is now 2018 and I'm not too sure we are allowed to have wives any more or allowed to say wife out loud.