Perhaps the network problem is only true for Ethereum when growth in number of projects & users in DeFi sector is too fast and bigger than growth of platform. The 15tps speed issue has been around since 2017 but until the end of 2020 ETH2.0 update is released and stage 0 is complete.
Other blockchains such as Cardano, TRON, Polkadot, WAVES, EOS... have enough capacity to support community, but very few DeFi projects exploit these blockchains because they still want to reach users belonging to Ethereum community.
The development of ETH2.0 as well as Polkadot will make it possible for all separate communities to interact with each other easily, the issue of transaction speed and cost will be resolved soon.