At current stage, those direction won't be looked by most people though. For example,
- RGB protocol and Taproot Assets for LN is far from ready to be used.
- RSK and Liquid (Bitcoin sidechain) are federated which is less decentralized compared with Bitcoin. Although RSK is somewhat better.
Other direction such as Drivechain is mostly unknown and i've no idea whether it's ready to use or not.
You're correct that most approaches are still in beta or testing stages. However, there have been some interesting developments relatively recently.
The most advanced project seems to be
Nomic (see
design document), but it has still centralized elements. It uses Tendermint as consensus mechanism (Cosmos platform) and their own token is premined. AFAIK this is already better than RSK (which has improved recently), it has to be further decentralized to really become an alternative for Bitcoiners (and not only "yet another Bitcoin bridge"). I believe with the current premined Nomic platform this wouldn't be possible, but what about a Nomic fork without premine (of course, this would probably need a PoW phase or similar "fair launch")?
Drivechain seems to depend on Bitcoin Script changes. The same is true for all rollup-style mechanisms which need covenants.
So my message to the developers would be: put these changes on the roadmap please! I understand that there may be risks and some devs may have other priorities, but I feel that there could be more research on these topics, and they are probably very important for Bitcoin's further adoption.