Let's be real for some moment here...
Stake's expenses are rising constantly .... I think they are paying something like $11 000 000 per Week for the Weekly Bonus. They are also now helping to pay for Kick.com ($100 000 000 to acquire one popular Streamer)
They have a VIP system, where players are constantly going up in ranks.... so the expenses are just going higher. At some stage.... this is going to be hard to fund this. Eddie saw the potential in Kick, when Twitch started to ban gambling content.... so he jumped onto it... so Kick can be a much bigger money spinner, if they can reach the same level as Twitch.
My prediction.... The VIP program and the bonuses will get constant tweaks to make it more affordable for Stake and less advantageous for the players. (Example : Hosts being tuned for the VIPs / Wagering focused on activities that takes the most money back...)
These giveaways are nothing. Not worth even mentioning.
See it that way, the weekly bonus isn't even 1% rake back or bet back (i used toe be at least), the house edge starts from 1% and goes up to double digit %.
So, you have to wager around 1000$ to get back around 1$. Though with the smallest house edge you have to lose 10$ to wager 1000$.
In other words. Of 10$ they earn, they give back 1$ but more likely much less, and that is the ABSOLUTE maximum. And also about these bonuses, they get back most of it anyway. You think players withdraw them?
It's like giving drugs for free when you are a drug dealer. It's a good strategy cause the addicts come back for more.
It's just more fun. And increasing your bets by one cent after several losses is affordable. 
