you can’t get the required tps for this. observability would also be bad between blocks and you would also have states where you could end up with different pixels based on the block that won.
Are you talking about a specific blockchain or categorically condemning all L1s? Solana could definitely handle the level of tps for something like this. A cache could handle the observability issues and you can just keep the old pixel until the transaction goes through.
Other L1s can also probably handle it. Not at the latency that Solana could but I see a lot of other low cost high tps L1s handling something like this easily.