According to this article Chinese chip maker SMIC is making 7nm chips using deep UV (DUV) as opposed to extreme UV (EUV). It can be done, although it’s more expensive. The article states that Taiwan Semiconductor and Samsung made 7nm chips using DUV before switching to EUV.
7nm seems to be doable with DUV and we certainly shouldn’t sell the chinese DUV equipment! Samsung and TSMC are preparing to use EUV for 3nm though.