After the Netherlands announced it would stop selling even second-tier chipmaking tools to China, the Chinese embassy sent them a frowny face emoji.

tomshardware.com/news/china-wants-netherlands-to-not-ban-exports-of-asml-tools

There is only one company in the world (ASML based in The Netherlands and probably the most important company in the world now) that makes the most advanced equipment for producing silicon chips, and they're also a key supplier even for less-advanced devices. So this not only prevents China from making chips on advanced processes of 7nm and below, it will cripple the country's ability to produce chips at 14nm over time. It already has machines since they were not previously restricted, but now it can no longer buy more or procure replacement parts.

That pushes them back to 28nm (the 20nm node sucked except for Intel's proprietary version) and 28nm when TSMC is ramping up 3nm will not get you anywhere.

The restrictions also hit flash memory, DRAM production, and logic chips like microprocessors.

Can China build its chipmaking tools? Sure. When not sure, it could be a few years or two decades. Even if they steal the designs, which they probably already have, they currently need the factories to make the parts to make the machines to make these machines.