Is there a website where I can view the wealth distribution of BTC and different altcoins?
I know such data are only estimates (address != holder, exchange wallets, etc.), but would still like to get a feeling of how different coins are distributed among its holders.
There is no consolidated data about that but you can search it individually, there are plenty of websites that provide different datas about coin distribution or different blockchains. Maybe one day someone can provide that info in the future but it will be a very ardous job and will eat more time.