Yes, marriage will be meaningless.
Possibly the only way to reverse course on this, would be to rescind governmental and employment benefits regarding marriage and family status. Some think that the push for homosexual marriage was to get homosexual partners on employer based health insurance plans, for example. If such incentives to get benefits based on family status are gone, then perhaps few homosexuals and others would bother getting married.
I have always felt it wasn’t about benefits but more to force schools to push on kids as an alternative lifestyle.
Marriage will be meaningless only if you let it be.