I thought they would fall quickly, too, and I got a lot of shit for it back in the day. Here's an example of the mainstream thinking back then https://www.nytimes.com/2022/1...
"...it is only a matter of time before control of Crimea is re-established."
NYT was very confused at the start of that war. A few days before the start of the invasion they decried Zelenskiy, whom they thought of as a light weight easily pushed over by the Russians. Their incompetent reporting might have been caused by the sudden and very successful Ukrainian counter attack in 2022, and the unreasonably high expectations many had for spring 2023 ("Here come the unstoppable Leopard 2 tanks"). NYT's predictive power was abysmal back then.
Turned out Ukraine was more prepared than we thought. Well the US had been preparing them for it since Maidan, arming and training, and building up the army. But the basic war math is that Russia has three times the recruitment pool and had six times the materiel before the war, and has had made bigger advances in production than the West. This basic math says that Ukraine can not hold out indefinitely, and so does them running thin on manpower for about two years already.
The USA have prepared, armed and equipped Iraq in the naughts, only so see everything crumble when ISIL popped up. The USA have also prepared, armed and equipped the Afghan army, which also didn't last.
Contrary to what we saw in the middle east, Ukrainians actually know, what they fight for. After over 100 years under the Russian shtick, interrupted only by a few years of Nazi German invasion (which was even worse), they were sick and tired of Russia and wanted to turn towards Europe. While we westerners whine about their own decline, our "failing civilization" is light years ahead of anything Russia ever produced. This is what Ukrainians are fighting for, this is what turned all these "expert" predictions to dust.
BTW the same "experts" have also proclaimed for years now, that Ukraine will run out of man power, which they evidently haven't.
To propose that Ukraine can not only win, but to also reclaim Crimea, as was the popular idea back in the day, is to propose something that can neutralize and flip around Russian advantage.
These late 2022 "expert" predictions of "Ukraine will reclaim Crimea soon" came about, because these "experts" thought, that a few Leopard 2A4 tanks would turn the tide. They would cut to Berdyansk, cut off Crimea and finish the Russian army. None of these "experts" expected the Russian lancet drone and its ability to turn Leopard 2A6 into scrap metal in quantity.
As you can see, Ukraine is now apparently done with these "experts" and has become self mostly reliant. Russian army is not (and never was) afraid of colossal losses of their own and still can't move forward any longer. Russians have to support a huge army while their economy falters. If you see two forces in some sort of stale mate, and one side declines while the other one rises, then you may see the writing on the wall: Russia will lose.
Despite regular news articles about the next big thing coming in to turn the tides, nothing of the such has materialized so far. It is my understanding that at least some in DC sincerely thought that Russia was going to crumble and go into a regime change based on the sanctions alone. Considering sanctions have never achieved that, instead always unifying and strengthening the resolve of the sanctioned country, this is... wild.
While economic sanctions by the west were frequently countered by bad actors (China, Orban/Vucic/Fico in Europe, MAGA in the USA, Turkey, arab countries), their recent kinetic sanctions do seem to have an effect. Russian economy is on the decline not according to western "experts", but according to Russian economists in Russia. They are in the same state as central powers in WW1: not yet beaten, but you could see where it's heading.
