The Russians certainly did scale up as you say, but there are underlying issues that have remained with them. Captured equipment has shown issues, some of which are potentially fatal to the user. The quality of work is poor and leads to a high failure rate. They do, however, make plenty of them - which has an advantage. Go to the war museum and look at any soviet tank built between 1940 and 1945, the welds look terrible and some are even missing the full complement of armor plating. They made thousands of them though.

The Western powers are not treating the situation as if they themselves were at war, hence no drastic changes in economic output to favor war machines. We have increased production though. Can't say how much, but it would raise eyebrows. I feel we should have been far more generous with the munitions, especially the older aircraft (think F-16, F-18) early on.

The certificates are basically just a paper trail. The aluminium is aircraft grade, the optics in spec, EMI shielding is sufficient, etc. We do extensive testing, but things slip through. Some issues are storage-related, and others are issues that don't show up til years later - such as microscopic ESD damage. Much of what we've been giving Ukraine was in storage for a while.

And now imagine how that stuff would work if certification requirements were lower.

Regarding China, I thought the same thing. Until Ukraine. Because as it turned out, that being at constant, if low intensity, war for basically all the time since Vietnam and Korea (at least since Gulf War 2 over Kuweit), really has benefits for the warfighting capability of countries. NATO, and especially the US, have that. Russia and China don't. And it shows, Russia didn't walz over Ukraine the way the West did over Iraq. And China has to deal with an amphibious invasion against a country that had decades to prepare for just that. Which leaves the question of supply lines across the pacific for a prolonged conflict. And there my money really is on western navies.

Just as a reminder, Russia is at a war economy by now, and still has to source from North Korea. All the while, NATO countries are just emptying stockpiles and slowly, maybe too slow, replenishing them. And despite that, all Russia got is a stalemate.