Lesley - there are different types of 'rich' you might be 'asset rich' if you own a house that's 'worth' £2m (although if it's not for sale, you don't really know what it's worth if you don't know what anyone will actually pay for it), that doesn't mean you are 'cash rich' and have a great deal of money.
Our house has apparently increased in value by £100k compared to when we bought it. I don't have £100k, I would have to sell, hoping i got that (paying estate agent fees etc) and go live somewhere smaller (which will also have increased in value in that time) to get that money. We intend to stay here for another 15 years, in that time, house prices might crash, they might stay as they are but inflation reduce the 'real value' of that £100k, they might go up further, but until that time, it's sort of pointless to talk about my 'profit' from the house, I need to live somewhere so I can't access that money. It's purely 'paper riches' not actual riches.
This is rather different to art, shares, jewellery etc, you don't need to have these things, houses are different, they aren't just assets, they are homes, if you sell your home, you need to get another one, you can't live nowhere. You can't just sell and use the money for other things (like you could with any other asset), you will need somewhere to sleep. (Granted, it could be somewhere smaller/cheaper.)