Don't be ridiculous. Just admit you're going off vibes and let it go.

I was born right after the collapse of the Soviet Union. I have experiences of my parents. I have experiences of my parents' friends. I have experiences of my teachers.

If everyone engaged in it, it's not a mechanism for inequality.

Yes it is, because some things are in higher demand than others. Cashiers and cooks were like gods that got the first picks and everyone else had to pick what's left.

You can measure so-called baskets and translate the goods and services to international prices.

The "baskets" were mostly empty, the pantries were often full. Things such as mayonnaise and canned peas were highly sought after deficit goods that were hard to acquire.

If everyone had access to free healthcare,

Bribing the doctor was expected if you needed anything more than a checkup.

education to the highest level,

was only available to the best students, once again encouraging bribery.

housing costing 3% of the monthly income,

that you could hardly acquire, some people waited up to 30 years to be allowed to buy a flat and many lived in dorms with other people. I grew up sharing 67 square meter flat with 12 other people.

there was no unemployment,

because it was illegal, but firing someone was very difficult as well, encouraging laziness, theft and alcoholism in the workforce.

Also, the competition for prestigious positions was fierce and often skewed by the favour system as well. My mother-in-law's math teacher gave her a bad grade because the in-laws' cousin got a position the teacher wanted for herself, sabotaging my mother-in-law's chances at a higher education as a result. My mother-in-law later became a cashier at a local store and never sold the teacher any under the counter goods. They are both still alive and still hate each other to this day.

and as you say a huge chunk of consumption was heavily subsidized, all of that points to inequality being low.

So was most of the production, because most factories would have collapsed without it. If it wasn't for the oil fields in Siberia, Soviet Union would have collapsed much earlier.

Also, especially before Andropov, many factories produced things illegally just so they could buy things such as tools and machinery illegally. A nearby ship factory produced car trailers (a highly sought after deficit product) that they would sell for US dollars locally to buy other deficit goods needed for shipbuilding such as welding masks and gloves.

The entire point that you're making, apparently, is that while in capitalism the mechanisms that lead to inequality of consumption are legal, in the USSR they were illegal. That's not pointing in the direction you want it to point, and you're only looking ridiculous because you're clearly not speaking from data but from vibes.

They were technically illegal but seldom punished. In fact, making deals and trading favours was a way of life.

Unlike in capitalism, where companies deciding how to do their own accounting without external supervision are surely not lying to anyone

At least you have the state statistics department and independent organisation checking their claims. As per Wikipedia:

Studies of second, shadow, grey and other economies are difficult because unlike official economies there are no direct statistics, therefore indirect methods are required.[2] Treml and Alexeev studied the relationships between per capita legal money income and such income-dependent variables as per capita savings and purchases of various goods and services. The study indicated that the disparity between legal income and legal spending gradually grew during 1965–1989 and by the end of the period the correlation between the two almost disappeared, indicating the rapid growth of the second economy.[2] The proliferation of the second economy was impossible without widespread corruption.[4]