By the way, there is staking-like feature called locktime/timelock on Bitcoin, which existed before ordinary altcoin staking started, that could be repurposed for staking, or we could just use decentralized smart-escrow for slashing purposes to penalize contract breach while bitcoins are locked (and possibly earning interest)..
I feel like the goal is way too different for that. Sure there's a locking mechanism there, but the idea behind that (and the system surrounding it) feels too different that reworking one or the other probably won't be that simple. Beside, where would the interest comes from and why does it needs to have one? Especially if the user are the one who're locking their coins. It's not like the network has any incentive to centralize coins (increase in hashpower, etc). CMIIW.
Staking is different because Bitcoin is not Proof of Stake.
Then when people want to stake, they have to do a first risky step, selling their bitcoin and buying Bitcoin wrapped tokens (there are many Bitcoin wrapped tokens), and staking those tokens.
During staking time, there is risk from locktime in staking pool while you never control what will happen with a project behind that staking pool. They can abandon their project, do a scam exit or just get hacked and bankrupted.
If people have bitcoins, they must be aware of a fact that they already have a very valuable asset, so it's their responsibility to keep that asset safely and securely. If they can hold their bitcoin safely and securely, they will get profit, and no need to take risk with Wrapped Bitcoin tokens and staking.
