If you are doing an NFT transaction on Opensea, you fill find that are two blockchains: Ethereum and Polygon.
We can't discuss that Ethereum is the most popular blockchain for NFTs. But why?
ETH is a decentralized blockchain platform that establishes a peer-to-peer network that securely executes and verifies application code, called smart contracts. Although it has high gas fees, is more secure, has auctions and in general, is more popular.
Most creators choose ETH, because it mitigates users from spamming the network. However, is currently undergoing some massive updates, that will change the network mechanism from the Proof-of-work (PoW) to a Proof-of-Stake model. This will help transaction fees going down and speed up.
Opensea supports also Polygon to create and sell NFTs.
Polygon, also known as Matic Network, is a secondary scaling solution or a "sidechain" that runs alongside the Ethereum Blockchain. This allows speedy transactions and low fees and one of its mission is to aggregate scalable solutions to support multichain Ethereum ecosystem.
THEN, WHICH CRYPTO CAN YOU USE FOR MINTING?
In case that your audience is immersed in the NFT space and the idea is not to buy at a higher price, the Polygon is your crypto.
Since it requires a little more steps, like converting ETH to Polygon, your audience should be a little more experienced in the NFT space.
But if you have larger audience and they are pretty new to NFT's, then better to launch on Ethereum, since it is more acknowledged for people, sending them more security. It helps to generate more hype and give the more security.