Baseload coal only runs at 60% these days because clean energy is supplying around 40% of the power at a cheaper price.
lf coal chose to directly compete with renewables it would be running at a loss some of the time. That's why it doesn't run at the high rates that it did previously when there was no wind or solar in the system .
Coal is only making money when there is no solar or wind generation . Look at the historic chart below. Previously coal generated nearly all our electricity . So, except for maintenance downtime and periods of low demand ( 5-10 % ), coal fired power stations ran all the time . Hence the 90% uptime that the LCOE was based on .
These days there is competition in the market that can produce electricity at a cheaper price.