Its not about time vs effort - choosing to refresh for 2200 crystals is time vs effort, that's the model of the game agreed. For a new player starting from 0 shards- 17 months is enough time for anyone to grind any single character, the issue is waiting 2 years (by Ultras admission) to hit 4mil GP then starting a 17 month grind.
If your 3mil GP you're likely to still be at least 100 shards away from completing which is 5 months by which point you're likely to be hitting 4mil GP so I'm struggling to see what the gp gate is for?