A machine that operates continuously is a perfect machine, and no machine is perfect.
The greater the number and diversity of machines, as well as their geographical dispersion, the greater their availability.
In this respect, a mix of renewables (solar, wind, geothermal, biomass, etc.) deployed on a continental scale, along with storage (batteries and V2(G|H), hydro, green hydrogen...) is unbeatable (total cost, availability, risk, etc.).
See for example Oskarshamn 3 in Sweden having a 7 month long unscheduled outage this year.
Ringhals 4 had an 8 month unscheduled outage during the energy crisis.