WH: Welcome to the forum!
People get walk-in permits all the time. You are much more likely to get a walk-in permit than finding someone willing to bring you into their group. (They cannot "give" you one of their permits, since that slot is assigned to their group.)
Some people have reported not getting a walk-in permit at times, but if you show up at 11 a.m. (for the overnight permits starting the same day), or 2 p.m. (for next-day day hike permits), you are very likely to score. Show up a second day if necessary.
Check out the Unused Permits
page. You can see there are many days where, even after ALL walk-in requests were satisfied, there were still permits available.
Or... call the wilderness permit number and ask if anything is available in your date window. People call and cancel many times, especially a week or less before their hike date. Call several times a day.