Why is there such a huge difference between provider.gasPrice and provider.maxFeePerGas?

When I call gasPrice and maxFeePerGas I am getting:

var rates = await provider.getFeeData();
ethers.utils.formatUnits(rates.gasPrice, 9); //=15.3399
ethers.utils.formatUnits(rates.maxFeePerGas, 9); //= 30.1798
ethers.utils.formatUnits(rates.maxPriorityFeePerGas, 9); //=1.5

But according to Gas Tracker ( https://etherscan.io/gastracker ) I should be getting:

Low: 14 gwei
Medium: 15 gwei
High: 15 gwei

According to the Internet, gasPrice is a legacy method and overestimates the gas price. But as you can see above, it seems it produces a gas price that is closest to Gas Tracker.

If in my code I used maxFeePerGas then wouldn't I be overpaying for gas?

You can get bonuses upto $100 FREE BONUS when you:
💰 Install these recommended apps:
💲 SocialGood - 100% Crypto Back on Everyday Shopping
💲 xPortal - The DeFi For The Next Billion
💲 CryptoTab Browser - Lightweight, fast, and ready to mine!
💰 Register on these recommended exchanges:
🟡 Binance🟡 Bitfinex🟡 Bitmart🟡 Bittrex🟡 Bitget
🟡 CoinEx🟡 Crypto.com🟡 Gate.io🟡 Huobi🟡 Kucoin.