Millions of VC funding dollars are going into Layer-2 solutions like Optimism, Arbitrum and Polygon to allow users to side-step mainnet Layer-1 and process transactions at a thousandth of the cost and speed just because Ethereum does not yet scale according to demand.
What if Vitalik pulls Eth 2.0 off and Layer-1 mainnet finally does scale with sharding, Purge, and the whole nine yards? Will all of these roll-ups and Layer-2 solutions that provide a temporary cosmetic fix just fall off the face of the earth and become obsolete, or would they still be thousandths of the cost of the new light-speed Eth 2.0?
Best Answer
Now this is just my speculation, but I don't think L2s will disappear. There is no way to get all three components right of the blockchain trilemma: security, decentralization and scalability. Ethereum is pretty good currently on the two first, but the last one is lacking.
To scale Ethereum you either have to go to L2 or try to improve L1 somehow. Yes, there are lots of plans on how to make L1 better (such as sharding), but I don't think any one them can get close to the required levels.
I believe L1 will mostly remain as a good source of security and decentralization. Different L2s then add more various features - one of them being scalability.
L2s don't offer just scalability, though. They can offer also stuff like privacy (for example Aztec) or aggregate transactions (for scalability purposes or something else).
P.S. I strongly disagree with the terminology of "what if Vitalik....". There are hundreds or thousands of people working on making Ethereum better. Furthemore, the term "Eth 2.0" is obsolete.