Yes there is also a downside of Polygon as well when dealing with other coins and tokens to either buy or sell. You also mention about Binance Smart Chain, but they too have downside which is similar to Polygon that is network congestion.
It works like this, always in crypto. When a new chain with new technology launches, it has lot of promise, and works fine. Time goes, network becomes bigger and hits its limit. Then congestion comes and the growth is down. Ethereum, Binance Smart Chain, Polygon, Solana. Soon we will have chance to witness it again with Avalanche.
But I know that the Digital Gold team is not closing their doors in moving to another blockchain. As ETH 2.0 seems not likely anymore but rebranding to consensus layer, I just don’t know though if the team keep their faith in Ethereum. Coz’ only those traders using the ETH blockchain who can afford to pay such fees are big timers. Not just one time, but either a few or more times.
Ethereum is a safest altcoin network and I think it is a second safest network in crypto, just behind Bitcoin network. I understand why the GOLD team want to stay with Ethereum. However, on the other side, transaction fee on this network is painful for users. It does not hurt big users but for small users, it is painful actually.
I do not complain about it but it is fact about Ethereum and ERC-20 chain.