I think I had hopes that the initial sidechain proposal by blockstream would have panned out. I think that would have lead to rapid experimentation and development but it never came to fruition.

I haven't looked enough into BIP-300/Drivechains but they offer a similar promise. I'd love to better understand the arguments against it but in general would love to get something like it eventually. Perhaps the best we can do are federations like liquid and fedimint though.

With that said, I am generally a proponent of the 'take it slow and don't break things' approach when it comes to bitcoin. It's definitely not the way you should build a business but when it comes to a once-in-a-human-history project like bitcoin I'd prefer to make sure we don't screw it up.