In the year after the 2018 peak, fees approached zero, but in the year after the 2021 peak, they stayed higher. As long as that keeps up and they don't actually go to zero, and people are competing for block space, miners will keep lining up, and the network will be fine.
Halvings matter less as time goes on. I didn't shed any tears for miner incentives when the reward went down by 25, and I won't shed any tears when it goes down by a mere 3.125. Mining was never meant to be profitable beyond BTC's bootstrapping phase. In fact the protocol actively makes difficulty adjustments to keep profitability near zero. Let their profits go down. As long as people are competing for block space, and transaction fees keep coming in, miners will continue competing for their fractions of a percent, and the network will be fine.