JayJuanGee quoted my post so I checked his post and found him answer your questions, not that his answer wasn't correct, but I thought I need to add an important fact that many people seem to be unaware off is that not all miners are friends, they don't know each other, they share one interest and one interest only (making the most profit).

If there was a universally agreed upon way to increase their profit, they won't even have to discuss it on forums or send emails, everyone would be doing it and it would just happen, and given that miners have been mining for over a decade, regardless of how miners as people change, the mindset is the same.

Many people like to come up with all kinds of different theories on how miners could do x to achieve z, you got a theory that suggests miners can intentionally shut down some of their gears to achieve.

1- Lower difficulty for the next epoch.
2- Fewer blocks found > larger amount of stuck transactions > more fees.

You got another theory that suggests, miners can shut down 90% of their miner gears, save 90% on operational and power costs, and still make the same money since the rewards are the same.

You got many more weird theories that all look great on paper, but can't be done simply because the nature of Bitcoin mining is decentralized, if 10,000 miners agree to exploit something based on one of the theories, I myself as a miner will make more money by exploiting their exploit, i.e if they shut down 90% of their gears, I will power 100% of my gears, a dozen thousand miners will do the same, so that 10,000 miners will actually lose money simply because they can't tell me or anyone else how to operate.

in fact, even if 90% of miners agreed to apply one of the theories, the remaining 10% can rekt the whole plan and eat the profit that 90% left on the table before any of their goals are achieved.

As long as you don't need a license from a single entity like the U.S., British or Russian government to mine BTC, there is exactly NOTHING miners can do to hurt BTC or its users without hurting themselves even more.

I rather worry about being hit by a lightning strike in the middle of the summer than worry about any of those theories surrounding miners becoming true in real life.

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In the recent high fee waves, some serious hashrate was lost, it was as large as 10% and then quickly settled at 6% (could be lower or higher depending on the luck status which we can't tell), someone might assume that some miners intentionally did that to clog the network even more and cause fees to rise so the remaining hashrate they had left online would make more money, but that is just theory, if we run the math (we did so many times in the Mining section) you will see that that 6% would have made more money by just mining rather than playing any kind of games and taking a huge risk.