https://consensys.net/knowledge-base/ethereum-2/faq/
Ethereum 2.0 is planned to be rolled out in at least three phases: Phase 0, 1, and 2. Phase 0 is planned to launch in 2020, with Phases 1 and 2 to be released in following years.
Phase 0: In the first phase of Ethereum 2.0, the “Beacon Chain” will be implemented. The Beacon Chain stores and manages the registry of validators, and will implement the
Proof of Stake (PoS) consensus mechanism for Ethereum 2.0. The original Ethereum PoW chain will continue to run alongside the new Ethereum PoS chain, ensuring there is no break in data continuity.
Phase 1: The second phase of Ethereum 2.0 will likely roll out in 2021. The primary improvement of Phase 1 is the integration of shard chains. Shard chains are a scalability mechanism in which
the Ethereum blockchain is “split” into 64 different chains, which allows for parallel transaction, storing, processing of information. At its most conservative estimate it will enable 64 times more
throughput than Ethereum 1.0, but it is designed to be able to handle several hundred times more data than Ethereum 1.0.
Phase 2: The third phase of Ethereum 2.0 will likely be launched in 2021 or 2022. This phase is currently less clearly defined than the above two phases, but will involve adding ether accounts and enabling transfers and withdrawals, implementing cross-shard transfers and contract calls, building execution environments so that scalable applications can be built on top of Ethereum 2.0, and bringing the Ethereum 1.0 chain into Ethereum 2.0 so that Proof of Work can finally be turned off.
Many further improvements are planned for research and development after Phase 2 is complete. Vitalik provides insight into some of these improvements in this easy-to-digest diagram.
Conclusion :
Scaling through sharding takes place in phase 1 & 2. That is when network congestion & associated high gas fees gets fixed (in theory).
PoS takes place in phase 0, that is scheduled for end of this year (soft target). PoS will not fix network congestion or fix high gas fee.
With phase 0 (PoS) already delayed a few times, i suspect phase 1 (with the scaling solution and planned for 2021) will also get delayed.
Always remember that ETH 2.0 is a multi-year update.
If you want to have fast and secure transactions with low fees, then find another network. This Ethereum network will stay congested for some years.