It's not appropriate to think of the solar panel as a constant source of power, but the solar panel manufacturing plant. All of our nuclear reactors and fuel are produced in-country, whereas china has dominated solar panel manufacturing and can cut us off. We need to be proactive about manufacturing.
A spent solar panel contains the exact materials needed to make a new solar panel. Chemical changes are cheaply reversible, so you can turn an old solar panel into a new one for less energy than it will produce during it's lifetime. A solar panel factory can operate indefinitely. (Or at least for as long as their is solar energy available.)
Nuclear fuel must be mined. Nuclear changes are reversible, but that requires the same amount of energy you would get back out. The Earth has a finite amount of nuclear fuel. (To be fair, there's a lot. The Earth contains enough fuel to last roughly the lifespan of the Sun.)
This supports your point even more!
China might be subsidizing solar panels today. We should load up while we can. Let them bear the initial costs. We should also spin up more domestic manufacturing (which was a component of the IRA). If/when foreign sourced solar panels are no longer available, you are in the exact same position you were the day before. All of that already installed generation capacity will continue to function for years before a crisis emerges.