I am probably most concerned about those other projects, I suspect there may be a tail risk to bitcoin being ossified before a few major updates, because people would rather use a side chain instead.

I imagine you could create a sodechain with 10MB blocks and it would run just fine, the fees would be nonexistent, the transactions per second would be huge, it would still be pegged 1-1 with bitcoin, it would take years before bandwidth or storage would be an issue. Everything sounds great, I'd even argue that such a thing is necessary whether its us increasing the L1 block size or a side chain. However, that is still not a solution to scaling bitcoin to 8 billion people, even if you put lightning on top. There are other upgrades that bitcoin is still going to need to scale that hard, we need people willing to go into the depths of mathematics and cryptography and dig out things like cross input signature aggregation, stuff that condenses data stored on chain to its tiniest possible size; then we can see the maximum benefits from things like side chains or block size increases.

So then, "its not because we want shitcoins on bitcoin", " its not because its fixes scalability", you could use it for testing improvements, but improvements should be carefully designed that we know they work before deployment, we shouldn't be throwing spaghetti at the wall and seeing what sticks. We have litecoin and testnet for those purposes.

What is the argument for drive chains? Its a serious question, I remember in Paul's episode he said its great because it kills shitcoins, but now that'd not the argument, arguments evolve that's fine. But what is the argument today, what do we actually stand to gain? A monero side chain certainly sounds cool, no knocking that, I guess some people really like smart contracts too, is that what you guys are after?