Can anyone explain to me how it works with what you can see on the blockchain and what you can't? If a wallet address generates a new receive address each time BTC is sent to it, then how can you see that wallet's balance on the blockchain, or can you?

So, this post stated that approx. 900,000 addresses hold >1 BTC in them. (1802) Congratulation for 900k whole coiners ! : Bitcoin (reddit.com)

Ok, so...if you can know that by looking at the blockchain, then what good does it do to generate a new receive address each time you receive BTC? Because a blockchain analysis will still know how much balance you've got in your wallet, right? I would appreciate if someone (who knows what they're talking about) could explain this to me in straightforward terms.

Basically, if you can know the balances of wallets on the BTC network by blockchain analysis, then what's the use of generating a different receive addy each time. And if it does skew the analysis (providing your privacy) when you generate a new receive addy each time, then how does the post above have even the slightest of accuracy in their information, and therefore any relevancy.

Help, I don't get it! Thanks.