The increase has mostly been caused by the interest in DeFi (Decentralized Finance). Interest has soared so users are submitting more transactions to participate in DeFi.
Here you can see the increase in interest (the amount of assets locked up in DeFi): https://defipulse.com/ . You can see that in maybe just two months the amount has gone up from 1 billion to over 6 billion. And the amount keeps on rising, so maybe transaction fees will also keep rising - who knows.