There isn't really anything stopping someone with status from being successful. At the same time, it doesn't really help them be successful either. The issue is the quality of life on the reserve.
You don't have to live on the reserve to have a status card, my grandmother never lived in Couchiching at any point in her life but was a member for over 20 years, my great grandmother lived there briefly after the residential school era then moved into the town (if native women married white men, they lost their status and had to leave—because it is not a race-based policy).
Most people here are just using it for the tax break, since Ontario has point of sale PST exemptions for status card holders (under certain conditions but you can never follow them or you get accused of racism so you just accept it every time—technically a fully native person who lives in the city should only ever use it for services, and never goods, but no one follows that rule). A lot of people bitch about it but I know several native people that never use them because of the racism they get when they pull the card out. On the other hand, I know several white people with native spouses (male and female) who take their spouse's card with them and use it when they shop because it's "for them" and "we live on the rez".
In the end the whole thing is an incredible hassle and on average, the customers at my work who use it to save money are saving less than $5.
With the exception of people with status who work on a reserve, all native people pay income tax on earned income like everyone else does. If they live on the reserve and work off the reserve (like those in Attawapiskat who work at the Victor mine), they pay income taxes. If the mine were located on reserve lands, they'd be tax exempt.