While "Unlimited" is a figure of speech, you can hit a point where you almost never pull common items:
Use an auto-clicker on the spawn blocks in a private server (if available) to cycle through blocks rapidly. The more you break, the higher your "Pity" counter rises, eventually forcing a high-tier drop. LUCKY BLOCKS Battlegrounds | SPAWN UNLIMITED LU...
Always check for active server boosts. Combining a Luck Potion with a Server Event can push your luck percentage into the thousands. While "Unlimited" is a figure of speech, you