Actually, the popular NFT platform that I know so far is on the OpenSea. I know that there are also many other platforms that provide NFT platforms. But, so far, I only follow the OpenSea.
However, if this is about the most secure platform, I think that as long as they are reputable, they may be secured. But not a guarantee 100% that they will be safe neough.
One of the most important things is that we must also check the smart contract so that we don't buy the fake NFT
I think that platforms can be very secure, have the best network, in fact there is a lot of talk about networks like Solana, Polygon, for having an enormous facility in that their fees are much cheaper, but given that NFTs have woken up in many people the total and wide distrust, it is normal that many people are reluctant to accept a good game or have doubts about their internal economy, and more so at this time when the BTC market has been so unstable, and not only due to the volatility of the BTC market, but it represents that for now there may be the possibility of lowering the BTC even more and if this happens any NFT or game can go lower, this is the greatest fear.