ETH MAINNET GAS FEES MADE ME CRY, YOU SHOULDN'T
First, lets get to the WHY of you should make xDAI chain your native home in metamask?
Every activities like approving your token to spend, swapping, sending, receiving (which in eth language is contract) are ridiculously expensive in Eth MainNet compared to xDai ChainNet.
Relate this figure:
So, if you want to do LONG TERM HODL which means if you are absolute sure that you are not going to spend that asset ,or feel the need to swap it to another token ,or say provide liquidity for 2-3 years, then there's no problem saving it in eth mainnet wallet. Afterwall, major exchanges like coinbase, binance only supports receival of that token only from eth mainnet wallet address.
Otherwise, if you feel the need to do all those activites mentioned above with the token, then preserve it in xDai net. Gas fees is 13000 times cheaper in xDai.
Eth mainnet will SWALLOW you up with gas fees without you even noticing it at once.
Second, lets get to the HOW of adding xDAI chain on your metamask.
Step1 a: Click the circle on Metamask
Step1 b: Click add Network
Step 1 c: Add this in the respective boxes:
Network name: xDai
RPC URL: https://xdai.poanetwork.dev
ChainID: 100
Symbol: xDai
Block Explorer URL: https://blockscout.com/poa/xdai
Step 2: Buy Dai on Uniswap (Switch back to the Eth Network)
Step 3: Convert Eth Network Dai to xDai Network (go here: https://dai-bridge.poa.network/ )
Step 4: Switch to xDai Network
a->Go to Honeyswap.org for swapping tokens from one to another.
b->Go to https://dai-bridge.poa.network for converting your Dai token in eth mainnet to mint native xDai. This xDai will be the gas fees here in xdai, just like eth is gas fees in eth mainnet.
c->Go to https://xdai-omnibridge.web.app/ for converting any of erc20 tokens in xDai net back to same erc20 tokens in eth mainnet. This service works vice versa also, meaning converting any in eth mainnet back to xDai.
Novice alert: Do not make mistake of converting Dai in eth mainnet to Dai in xDai net using option c. Yes, it will convert but it will not be xDai. There's b for that.