The problem with small nuclear reactors is that costs don't scale down linearly with size or power output. Like you still need about the same number of armed security guards to protect the site.
They might be a good option for remote sites off the grid where physical security isn't a concern.
They are scaled for politics.
Tell someone over 60 or 70 that Poland has better modular reactors than us, and they'll suddenly care.
Some costs scale down more than linearly, some less. For example, because of the square-cube law, you lose more neutrons through the walls of the reactor, so you often times need a higher level of uranium enrichment, and you produce less energy per ton of fuel, all other things being equal. That’s bad news for SMRs. But many reactor components, being significantly smaller, become much cheaper to manufacture, at least that’s the theory. We don’t know yet. But China is planning to start operating its ACP100 SMR in the next few months, and we will probably hear soon how happy they are with it.