1. Strong hands appear infrequently

It's not enough to wait for a good starting hand. You need to make a hand with it and then get paid. While you're waiting, your stack diminishes due to increasing blinds. Additionally, it shrinks because of hands where you put chips in the pot pre-flop but missed the board on the flop and just folded, losing part of your stack. 

Meanwhile, one small bet in a check to an opponent wins such pots with huge frequency. By never bluffing, you miss the opportunity to maintain your stack in the tournament, as the probability of missing the board is significantly higher than hitting it. 

2. Opponents easily adapt to this playing style

If you never bluff, it becomes clear to players: your bets indicate strength. They stop participating in hands with you, and your strong hands get paid less often. Thus, the main idea of playing without bluffing—winning at showdown—doesn't work. Easy adaptation of opponents to this strategy renders it useless. 

3. You don't win pots without showdown

In poker, a massive amount of hands end without a showdown. If you never attack without a strong hand, you voluntarily give up all these victories. You win only when the cards come, and you lose in other situations. Mathematically, this is unprofitable.

4. You don't develop the skill of reading bluffs

To read others' bluffs, you need to bluff yourself. Only then do you develop a sense of the plausibility of a line an opponent is playing, understanding inconsistencies and noticing moments where an opponent is 'feigning' non-existent strength. Without this experience, the ability to uncover others' bluffs develops much slower.

How to start bluffing?

If you're a beginner and want to gradually incorporate bluffing into your play, start with basic situations where the expected value is already on your side.

1. Place a continuation bet in heads-up pots in position

If you were the pre-flop aggressor, bet 30% of the pot on the flop, even if you missed the board. In most cases, the opponent will simply give up, and this action will be profitable in the long run.

2. Bet into the aggressor's 'bet check'

If the opponent was the pre-flop aggressor but didn't place a continuation bet, bet yourself.
If the opponent placed a continuation bet, you called, and they don't bet on the next street - bet yourself on the river.
Most opponents play honestly, and if they had a strong hand, they would continue investing in the pot. Their check is a signal of weakness for you. The frequency of folds in these situations is very high, so even a simple strategy of 'always bet' brings a profit. Later, you'll learn to distinguish between favourable situations for betting into a check and unfavourable ones.

3. Use semi-bluffs

If you have a drawing hand (e.g., a flush draw or straight draw), bet not only because you can make the opponent fold but also because you have a chance to improve your hand. In cases where your hand improves, the pot will be large enough to win even more chips with a potentially stronger hand.

4. Bet in situations where winning at showdown is impossible

If your hand cannot win at showdown, but the opponent shows caution and checks,  make a bet. This way, you'll at least sometimes win in situations where you otherwise couldn't and reduce chip loss over time.

Conclusion

Playing without bluffing seems safe only at first glance. In practice, it leads to chip loss, predictable play, and tournament eliminations. You don’t need to bluff big and often, but if you want to win over time, you must be able to take pots not only with strong hands but also with correct decisions in moments when the cards didn't help. This is what distinguishes a good player from someone who only relies on luck.