What a fee waiver actually means
Most paid cards waive the next year's annual fee if you spend above a threshold in the current year. Hit the threshold and the fee effectively becomes zero.
When a paid card beats a free one
If a card's rewards plus a waived fee out-earn a free card, the paid card wins. The break-even depends entirely on your annual spend.
The traps
Some waivers exclude rent, fuel, or wallet loads from the qualifying spend. Always check which categories count toward the threshold.