Why are Bitcoin miners unhappy for dozens of days every month?

A few days before the Chinese New Year, I was still working, took out my Bitcoin wallet, recharged it to the exchange, and sold the coins. This month, I lost 0.325 BTC from mining, which was really weird.
Americans have a Tax Freedom Day, which is used to count how many days it takes for Americans to earn all the taxes they need to pay. After Tax Freedom Day, you will truly work for yourself, and all the money you earn will go into your own pocket.
Americans have to pay a lot of taxes. They are really living in dire straits. Basically, they have to wait until April to earn back all the taxes they have to pay to the country for the year. In other words, Americans have to work for the country for more than one-third of their time.
We also set an electricity free day for mining. Every month, a portion of the coins produced by mining needs to be sold to pay for electricity. The electricity free day is to count the number of days in a month when the mining output needs to be sold in full to pay for electricity. Then on the remaining days, the mined coins belong to the miners themselves. Only when the electricity free day comes, can the miners earn coins happily.
I have hundreds of S9 mining machines. I am a miner, but I suffer much more than American taxpayers. American taxpayers only need to work one-third of their time for the country.
The electricity-free days for my hundreds of mining machines are basically around the 25th of each month. I can mine for less than 10 days a day. More than 2/3 of the time is mining and electricity-free days, and less than 1/3 of the time is electricity-free days.
When I bought the mining machine, I calculated that the electricity free day was around the 15th. It was really fun to mine at that time. The mining machine maintained its value, the electricity free day came early, and the price of the coins I mined was still rising.
Now for my mining machine, the electricity free day is around the 20th. Thanks to the rising price of coins, the computing power has not increased as fast as the price of coins.
The Electricity Freedom Day is mainly affected by three factors: the unit power consumption of the mining machine and the electricity cost; the total network computing power and the price of the currency. The lower the power consumption, the cheaper the electricity cost, the higher the price of the currency, and the lower the total network computing power, the sooner the Electricity Freedom Day will come. The first two factors are affected by miners choosing better mining machines and negotiating with the mining farm. The last two factors are up to fate.
Source: Internet