Another way to go is to use the web services to buy and receive cryptocurrencies on a wallet in a single step.
Some of these do not give the chance to do it directly on the Polygon blockchain, so the only thing to do is to “bridge” the tokens from the supported blockchain to Polygon.
Obviously, a gas fee is due in this operation. This expense becomes a significant percentage of the transaction if the intent is to make a small trade.
In addition to the cost of bridging, we need to consider the volatility of the blockchain ecosystem.
For this reason, it is difficult, perhaps impossible, to accurately predict gas transaction costs in this bridging process.
Therefore, the bridging operation always ends with the “sacrifice” of some native token, abandoned in the starting blockchain.
But the most important disadvantage is that all these solutions are created to sell cryptocurrencies, so they have to earn money on this business.