You do need a baseload,

Did you read the link in my post that you're replying to? It's from a former Federal Energy Regulatory Commissioner.

Here's another article on the subject:

"The old myth was based on the incorrect assumption that base-load demand can only be supplied by base-load power stations; for example, coal in Australia and nuclear in France. However, the mix of renewable energy technologies in our computer model, which has no base-load power stations, easily supplies base-load demand. Our optimal mix comprises wind 50-60%; solar PV 15-20%; concentrated solar thermal with 15 hours of thermal storage 15-20%; and the small remainder supplied by existing hydro and gas turbines burning renewable gases or liquids."

https://theconversation.com/baseload-power-is-a-myth-even-intermittent-renewables-will-work-13210

I'll skip over the rest of your comment as it's not really relevant.

But nuclear, even with its high initial capital cost and long build time, still does provide energy cheaply

It literally doesn't. See the graph I posted.

and will last for a lot longer than solar panels and wind turbines,

Nobody is arguing that. We're talking about cost and base load.

nuclear can be easily and quickly ramped up or down depending on the load required.

This is absolutely not true. It's also worth noting that nuclear needs to operate as close to 24/7/365 to be economically viable. It's a source of base load power, it's not dispatchable and can't be used as a peaker plant.