Statistically that's the fastest path.

Some regionals are paying pretty good right now. The delay for regional upgrade is not seniority... it's the 121 1000 hour requirement. If your regional still pays poorly, you can go to another one and take your 121 time with you. You'd lose time due to training pipeline, but if you really need more money that's an option.

If you don't need the money, just tough it out... you'll have more money than you know what to do with at the legacy. In my 20's and 30's I didn't spend money, focused on savings and career progression. That worked out well for me, on several fronts. You don't even actually need money when you're young, just beer and women.