Your example is ... , and assumes that
and you too make many assumptions
From your history of misinformation? Yes, easy assumption.
IF it's succesfully out of beta,
you think LN will be out of beta?.. well bitcoin(the separate network that uses a good blockchain security model) is 10 years old and devs are too afraid to say its out of beta. so dont expect anything different with ln, especially when LN is more flawed, buggy and impractical.
Is Bitcoin out of beta in your opinion? Do developers of Bitcoin Cash share this opinion? Because they should promote it as the "Bitcoin that's out of Beta". They fixed Bitcoin's limitations, right?

and accepted by the mainstream.
compared to a well advertised, talked about network called bitcoin thats 10 years old and still not main stream.. im starting to wonder how long you expect it to take to have LN 'mainstream'
But IF it stays as a niche for Bitcoiners, then yes.
stays as a niche for bitcoin.. ha.. never was.
remember bitcoin and other coins were edited to become LN compatible.
LN was node made to be bitcoin compatible
Never was? No one is using it? I'm confused.
So only a protocol that is set in stone and only changes for scaling / capacy demand adjustments and bug fixes is out of beta.
Second, full nodes are defined to mine, so they are properly incentified. Problem solved.
Nodes that dont mine are just slave nodes at some front end / fat client style - just listening what servers / back end nodes = miners have agreed on.