Dynamic pricing is generally fine so long as the sellers are not colluding. When courses have an incentive to undercut each other, it maximizes the producer AND
consumer surplus.
If however, the the producers collude to set minimum prices, they can capture the consumer surplus… which is a problem. If dynamic pricing extends to the point where it is offering different prices to different individuals based on ability to pay, it also begins to capture the consumer surplus, and is a real concern.
Simply charging more when demand goes up doesn’t actually veer into anti-competitive behavior.